Merge pull request #519 from ankostis/appveyor

Test project on Windows with MINGW/Cygwin git (conda2.7&3.4/cpy-3.5)

40 files changed, 1493 insertions, 1132 deletions

diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 00000000..47bd1f0b
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,83 @@
+# CI on Windows via appveyor
+environment:
+    GIT_DAEMON_PATH:   "C:\\Program Files\\Git\\mingw64\\libexec\\git-core"
+    CYGWIN_GIT_PATH:   "C:\\cygwin\\bin;%GIT_DAEMON_PATH%"
+    CYGWIN64_GIT_PATH: "C:\\cygwin64\\bin;%GIT_DAEMON_PATH%"
+
+    matrix:
+        ## MINGW
+        #
+      - PYTHON: "C:\\Python27"
+        PYTHON_VERSION: "2.7"
+        GIT_PATH: "%GIT_DAEMON_PATH%"
+      - PYTHON: "C:\\Python34-x64"
+        PYTHON_VERSION: "3.4"
+        GIT_PATH: "%GIT_DAEMON_PATH%"
+      - PYTHON: "C:\\Python35-x64"
+        PYTHON_VERSION: "3.5"
+        GIT_PATH: "%GIT_DAEMON_PATH%"
+      - PYTHON: "C:\\Miniconda35-x64"
+        PYTHON_VERSION: "3.5"
+        IS_CONDA: "yes"
+        GIT_PATH: "%GIT_DAEMON_PATH%"
+
+      #   ## Cygwin
+      #   #
+      # - PYTHON: "C:\\Miniconda-x64"
+      #   PYTHON_VERSION: "2.7"
+      #   IS_CONDA: "yes"
+      #   GIT_PATH: "%CYGWIN_GIT_PATH%"
+      # - PYTHON: "C:\\Python34-x64"
+      #   PYTHON_VERSION: "3.4"
+      #   GIT_PATH: "%CYGWIN_GIT_PATH%"
+      # - PYTHON: "C:\\Python35-x64"
+      #   PYTHON_VERSION: "3.5"
+      #   GIT_PATH: "%CYGWIN64_GIT_PATH%"
+
+
+install:
+    - set PATH=%PYTHON%;%PYTHON%\Scripts;%GIT_PATH%;%PATH%
+
+    ## Print architecture, python & git used for debugging.
+    #
+    - |
+        uname -a
+        where git git-daemon python pip pip3 pip34
+        python --version
+        python -c "import struct; print(struct.calcsize('P') * 8)"
+
+    - IF "%IS_CONDA%"=="yes" (
+        conda info -a &
+        conda install --yes --quiet  pip
+      )
+    - pip install  nose ddt wheel coveralls
+    -   IF "%PYTHON_VERSION%"=="2.7" (
+            pip install mock
+        )
+
+    ## Copied from `init-tests-after-clone.sh`.
+    #
+    - |
+        git submodule update --init --recursive
+        git fetch --tags
+        git tag __testing_point__
+        git checkout master || git checkout -b master
+        git reset --hard HEAD~1
+        git reset --hard HEAD~1
+        git reset --hard HEAD~1
+        git reset --hard __testing_point__
+
+    ## For commits performed with the default user.
+    - |
+        git config --global user.email "travis@ci.com"
+        git config --global user.name "Travis Runner"
+
+    - pip install -e .
+
+build: false
+
+test_script:
+    - nosetests --with-coverage
+
+#on_success:
+#    - IF "%PYTHON_VERSION%"=="3.4" (coveralls)
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 00000000..872b8eb4
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,2 @@
+git/test/fixtures/* eol=lf
+init-tests-after-clone.sh
diff --git a/.travis.yml b/.travis.yml
index 31f2c00c..ab766e7c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,7 +16,7 @@ git:
 install:
   - git submodule update --init --recursive
   - git fetch --tags
-  - pip install coveralls flake8 sphinx
+  - pip install coveralls flake8 ddt sphinx
 
   # generate some reflog as git-python tests need it (in master)
   - ./init-tests-after-clone.sh
@@ -31,8 +31,9 @@ script:
   # Make sure we limit open handles to see if we are leaking them
   - ulimit -n 96
   - ulimit -n
-  - nosetests -v --with-coverage
-  - flake8
-  - cd doc && make html
+  - nosetests --with-coverage
+  - if [ "$TRAVIS_PYTHON_VERSION" == '3.4' ]; then flake8; fi
+  - if [ "$TRAVIS_PYTHON_VERSION" == '3.5' ]; then cd doc && make html; fi
+  -
 after_success:
   - coveralls
diff --git a/README.md b/README.md
index b7e2b139..6632347f 100644
--- a/README.md
+++ b/README.md
@@ -1,20 +1,28 @@
 ## GitPython
 
-GitPython is a python library used to interact with git repositories, high-level like git-porcelain, or low-level like git-plumbing.
+GitPython is a python library used to interact with git repositories, high-level like git-porcelain, 
+or low-level like git-plumbing.
 
-It provides abstractions of git objects for easy access of repository data, and additionally allows you to access the git repository more directly using either a pure python implementation, or the faster, but more resource intensive git command implementation.
+It provides abstractions of git objects for easy access of repository data, and additionally 
+allows you to access the git repository more directly using either a pure python implementation, 
+or the faster, but more resource intensive *git command* implementation.
 
-The object database implementation is optimized for handling large quantities of objects and large datasets, which is achieved by using low-level structures and data streaming.
+The object database implementation is optimized for handling large quantities of objects and large datasets, 
+which is achieved by using low-level structures and data streaming.
 
 
 ### REQUIREMENTS
 
-GitPython needs the `git` executable to be installed on the system and available in your `PATH` for most operations. If it is not in your `PATH`, you can help GitPython find it by setting the `GIT_PYTHON_GIT_EXECUTABLE=<path/to/git>` environment variable.
+GitPython needs the `git` executable to be installed on the system and available 
+in your `PATH` for most operations. 
+If it is not in your `PATH`, you can help GitPython find it by setting 
+the `GIT_PYTHON_GIT_EXECUTABLE=<path/to/git>` environment variable.
 
 * Git (1.7.x or newer)
 * Python 2.7 to 3.5, while python 2.6 is supported on a *best-effort basis*.
 
-The list of dependencies are listed in `./requirements.txt` and `./test-requirements.txt`. The installer takes care of installing them for you.
+The list of dependencies are listed in `./requirements.txt` and `./test-requirements.txt`. 
+The installer takes care of installing them for you.
 
 ### INSTALL
 
@@ -31,7 +39,7 @@ Both commands will install the required package dependencies.
 A distribution package can be obtained for manual installation at:
 
     http://pypi.python.org/pypi/GitPython
-    
+
 If you like to clone from source, you can do it like so:
 
 ```bash
@@ -45,7 +53,7 @@ git submodule update --init --recursive
 #### Leakage of System Resources
 
 GitPython is not suited for long-running processes (like daemons) as it tends to
-leak system resources. It was written in a time where destructors (as implemented 
+leak system resources. It was written in a time where destructors (as implemented
 in the `__del__` method) still ran deterministically.
 
 In case you still want to use it in such a context, you will want to search the
@@ -61,17 +69,25 @@ as they are kept alive solely by their users, or not.
 
 ### RUNNING TESTS
 
-*Important*: Right after cloning this repository, please be sure to have executed the `init-tests-after-clone.sh` script in the repository root. Otherwise you will encounter test failures.
+*Important*: Right after cloning this repository, please be sure to have executed
+the `./init-tests-after-clone.sh` script in the repository root. Otherwise
+you will encounter test failures.
+
+On *Windows*, make sure you have `git-daemon` in your PATH.  For MINGW-git, the `git-daemon.exe`
+exists in `Git\mingw64\libexec\git-core\`; CYGWIN has no daemon, but should get along fine
+with MINGW's.
 
-The easiest way to run test is by using [tox](https://pypi.python.org/pypi/tox) a wrapper around virtualenv. It will take care of setting up environnements with the proper dependencies installed and execute test commands. To install it simply:
+The easiest way to run tests is by using [tox](https://pypi.python.org/pypi/tox)
+a wrapper around virtualenv. It will take care of setting up environnements with the proper
+dependencies installed and execute test commands. To install it simply:
 
     pip install tox
 
 Then run:
 
     tox
-    
-    
+
+
 For more fine-grained control, you can use `nose`.
 
 ### Contributions
@@ -84,7 +100,8 @@ Please have a look at the [contributions file][contributing].
 * [Questions and Answers](http://stackexchange.com/filters/167317/gitpython)
  * Please post on stackoverflow and use the `gitpython` tag
 * [Issue Tracker](https://github.com/gitpython-developers/GitPython/issues)
-  * Post reproducible bugs and feature requests as a new issue. Please be sure to provide the following information if posting bugs:
+  * Post reproducible bugs and feature requests as a new issue. 
+    Please be sure to provide the following information if posting bugs:
     * GitPython version (e.g. `import git; git.__version__`)
     * Python version (e.g. `python --version`)
     * The encountered stack-trace, if applicable
@@ -100,7 +117,7 @@ Please have a look at the [contributions file][contributing].
 * Finally, set the upcoming version in the `VERSION` file, usually be
   incrementing the patch level, and possibly by appending `-dev`. Probably you
   want to `git push` once more.
-  
+
 ### LICENSE
 
 New BSD License.  See the LICENSE file.
@@ -113,7 +130,8 @@ New BSD License.  See the LICENSE file.
 [![Stories in Ready](https://badge.waffle.io/gitpython-developers/GitPython.png?label=ready&title=Ready)](https://waffle.io/gitpython-developers/GitPython)
 [![Throughput Graph](https://graphs.waffle.io/gitpython-developers/GitPython/throughput.svg)](https://waffle.io/gitpython-developers/GitPython/metrics/throughput)
 
-Now that there seems to be a massive user base, this should be motivation enough to let git-python return to a proper state, which means
+Now that there seems to be a massive user base, this should be motivation enough to let git-python 
+return to a proper state, which means
 
 * no open pull requests
 * no open issues describing bugs
diff --git a/doc/source/conf.py b/doc/source/conf.py
index add686d3..2df3bbb6 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -50,7 +50,8 @@ copyright = u'Copyright (C) 2008, 2009 Michael Trier and contributors, 2010-2015
 # built documents.
 #
 # The short X.Y version.
-VERSION = open(os.path.join(os.path.dirname(__file__),"..", "..", 'VERSION')).readline().strip()
+with open(os.path.join(os.path.dirname(__file__),"..", "..", 'VERSION')) as fd:
+    VERSION = fd.readline().strip()
 version = VERSION
 # The full version, including alpha/beta/rc tags.
 release = VERSION
diff --git a/git/cmd.py b/git/cmd.py
index ceea2442..f4f5f99a 100644
--- a/git/cmd.py
+++ b/git/cmd.py
@@ -4,64 +4,53 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
-import os
-import os.path
-import sys
-import select
-import logging
-import threading
-import errno
-import mmap
-
-from git.odict import OrderedDict
 from contextlib import contextmanager
+import io
+import logging
+import os
 import signal
 from subprocess import (
     call,
     Popen,
     PIPE
 )
+import subprocess
+import sys
+import threading
 
-
-from .util import (
-    LazyMixin,
-    stream_copy,
-    WaitGroup
-)
-from .exc import (
-    GitCommandError,
-    GitCommandNotFound
-)
 from git.compat import (
     string_types,
     defenc,
     force_bytes,
     PY3,
-    bchr,
     # just to satisfy flake8 on py3
     unicode,
     safe_decode,
+    is_posix,
+    is_win,
 )
+from git.exc import CommandError
+from git.odict import OrderedDict
 
-execute_kwargs = ('istream', 'with_keep_cwd', 'with_extended_output',
-                  'with_exceptions', 'as_process', 'stdout_as_string',
-                  'output_stream', 'with_stdout', 'kill_after_timeout',
-                  'universal_newlines')
+from .exc import (
+    GitCommandError,
+    GitCommandNotFound
+)
+from .util import (
+    LazyMixin,
+    stream_copy,
+)
 
-log = logging.getLogger('git.cmd')
-log.addHandler(logging.NullHandler())
 
-__all__ = ('Git', )
+execute_kwargs = set(('istream', 'with_keep_cwd', 'with_extended_output',
+                      'with_exceptions', 'as_process', 'stdout_as_string',
+                      'output_stream', 'with_stdout', 'kill_after_timeout',
+                      'universal_newlines', 'shell'))
 
-if sys.platform != 'win32':
-    WindowsError = OSError
+log = logging.getLogger('git.cmd')
+log.addHandler(logging.NullHandler())
 
-if PY3:
-    _bchr = bchr
-else:
-    def _bchr(c):
-        return c
-# get custom byte character handling
+__all__ = ('Git',)
 
 
 # ==============================================================================
@@ -70,154 +59,63 @@ else:
 # Documentation
 ## @{
 
-def handle_process_output(process, stdout_handler, stderr_handler, finalizer):
+def handle_process_output(process, stdout_handler, stderr_handler, finalizer, decode_streams=True):
     """Registers for notifications to lean that process output is ready to read, and dispatches lines to
-    the respective line handlers. We are able to handle carriage returns in case progress is sent by that
-    mean. For performance reasons, we only apply this to stderr.
+    the respective line handlers.
     This function returns once the finalizer returns
+
     :return: result of finalizer
     :param process: subprocess.Popen instance
     :param stdout_handler: f(stdout_line_string), or None
     :param stderr_hanlder: f(stderr_line_string), or None
-    :param finalizer: f(proc) - wait for proc to finish"""
-    fdmap = {process.stdout.fileno(): (stdout_handler, [b'']),
-             process.stderr.fileno(): (stderr_handler, [b''])}
-
-    def _parse_lines_from_buffer(buf):
-        line = b''
-        bi = 0
-        lb = len(buf)
-        while bi < lb:
-            char = _bchr(buf[bi])
-            bi += 1
-
-            if char in (b'\r', b'\n') and line:
-                yield bi, line
-                line = b''
-            else:
-                line += char
-            # END process parsed line
-        # END while file is not done reading
-    # end
-
-    def _read_lines_from_fno(fno, last_buf_list):
-        buf = os.read(fno, mmap.PAGESIZE)
-        buf = last_buf_list[0] + buf
-
-        bi = 0
-        for bi, line in _parse_lines_from_buffer(buf):
-            yield line
-        # for each line to parse from the buffer
-
-        # keep remainder
-        last_buf_list[0] = buf[bi:]
-
-    def _dispatch_single_line(line, handler):
-        line = line.decode(defenc)
-        if line and handler:
-            handler(line)
-        # end dispatch helper
-    # end single line helper
-
-    def _dispatch_lines(fno, handler, buf_list):
-        lc = 0
-        for line in _read_lines_from_fno(fno, buf_list):
-            _dispatch_single_line(line, handler)
-            lc += 1
-        # for each line
-        return lc
-    # end
-
-    def _deplete_buffer(fno, handler, buf_list, wg=None):
-        lc = 0
-        while True:
-            line_count = _dispatch_lines(fno, handler, buf_list)
-            lc += line_count
-            if line_count == 0:
-                break
-        # end deplete buffer
-
-        if buf_list[0]:
-            _dispatch_single_line(buf_list[0], handler)
-            lc += 1
-        # end
-
-        if wg:
-            wg.done()
-
-        return lc
-    # end
-
-    if hasattr(select, 'poll'):
-        # poll is preferred, as select is limited to file handles up to 1024 ... . This could otherwise be
-        # an issue for us, as it matters how many handles our own process has
-        poll = select.poll()
-        READ_ONLY = select.POLLIN | select.POLLPRI | select.POLLHUP | select.POLLERR
-        CLOSED = select.POLLHUP | select.POLLERR
-
-        poll.register(process.stdout, READ_ONLY)
-        poll.register(process.stderr, READ_ONLY)
-
-        closed_streams = set()
-        while True:
-            # no timeout
-
-            try:
-                poll_result = poll.poll()
-            except select.error as e:
-                if e.args[0] == errno.EINTR:
-                    continue
-                raise
-            # end handle poll exception
-
-            for fd, result in poll_result:
-                if result & CLOSED:
-                    closed_streams.add(fd)
-                else:
-                    _dispatch_lines(fd, *fdmap[fd])
-                # end handle closed stream
-            # end for each poll-result tuple
-
-            if len(closed_streams) == len(fdmap):
-                break
-            # end its all done
-        # end endless loop
-
-        # Depelete all remaining buffers
-        for fno, (handler, buf_list) in fdmap.items():
-            _deplete_buffer(fno, handler, buf_list)
-        # end for each file handle
-
-        for fno in fdmap.keys():
-            poll.unregister(fno)
-        # end don't forget to unregister !
-    else:
-        # Oh ... probably we are on windows. select.select() can only handle sockets, we have files
-        # The only reliable way to do this now is to use threads and wait for both to finish
-        # Since the finalizer is expected to wait, we don't have to introduce our own wait primitive
-        # NO: It's not enough unfortunately, and we will have to sync the threads
-        wg = WaitGroup()
-        for fno, (handler, buf_list) in fdmap.items():
-            wg.add(1)
-            t = threading.Thread(target=lambda: _deplete_buffer(fno, handler, buf_list, wg))
-            t.start()
-        # end
-        # NOTE: Just joining threads can possibly fail as there is a gap between .start() and when it's
-        # actually started, which could make the wait() call to just return because the thread is not yet
-        # active
-        wg.wait()
-    # end
+    :param finalizer: f(proc) - wait for proc to finish
+    :param decode_streams:
+        Assume stdout/stderr streams are binary and decode them vefore pushing \
+        their contents to handlers.
+        Set it to False if `universal_newline == True` (then streams are in text-mode)
+        or if decoding must happen later (i.e. for Diffs).
+    """
+    # Use 2 "pupm" threads and wait for both to finish.
+    def pump_stream(cmdline, name, stream, is_decode, handler):
+        try:
+            for line in stream:
+                if handler:
+                    if is_decode:
+                        line = line.decode(defenc)
+                    handler(line)
+        except Exception as ex:
+            log.error("Pumping %r of cmd(%s) failed due to: %r", name, cmdline, ex)
+            raise CommandError(['<%s-pump>' % name] + cmdline, ex)
+        finally:
+            stream.close()
+
+    cmdline = getattr(process, 'args', '')  # PY3+ only
+    if not isinstance(cmdline, (tuple, list)):
+        cmdline = cmdline.split()
+    threads = []
+    for name, stream, handler in (
+        ('stdout', process.stdout, stdout_handler),
+        ('stderr', process.stderr, stderr_handler),
+    ):
+        t = threading.Thread(target=pump_stream,
+                             args=(cmdline, name, stream, decode_streams, handler))
+        t.setDaemon(True)
+        t.start()
+        threads.append(t)
+
+    for t in threads:
+        t.join()
 
     return finalizer(process)
 
 
 def dashify(string):
     return string.replace('_', '-')
-    
+
 
 def slots_to_dict(self, exclude=()):
     return dict((s, getattr(self, s)) for s in self.__slots__ if s not in exclude)
-    
+
 
 def dict_to_slots_and__excluded_are_none(self, d, excluded=()):
     for k, v in d.items():
@@ -227,6 +125,15 @@ def dict_to_slots_and__excluded_are_none(self, d, excluded=()):
 
 ## -- End Utilities -- @}
 
+# value of Windows process creation flag taken from MSDN
+CREATE_NO_WINDOW = 0x08000000
+
+## CREATE_NEW_PROCESS_GROUP is needed to allow killing it afterwards,
+# seehttps://docs.python.org/3/library/subprocess.html#subprocess.Popen.send_signal
+PROC_CREATIONFLAGS = (CREATE_NO_WINDOW | subprocess.CREATE_NEW_PROCESS_GROUP
+                      if is_win
+                      else 0)
+
 
 class Git(LazyMixin):
 
@@ -246,35 +153,31 @@ class Git(LazyMixin):
     """
     __slots__ = ("_working_dir", "cat_file_all", "cat_file_header", "_version_info",
                  "_git_options", "_environment")
-                 
+
     _excluded_ = ('cat_file_all', 'cat_file_header', '_version_info')
-    
+
     def __getstate__(self):
         return slots_to_dict(self, exclude=self._excluded_)
-        
+
     def __setstate__(self, d):
         dict_to_slots_and__excluded_are_none(self, d, excluded=self._excluded_)
-        
+
     # CONFIGURATION
     # The size in bytes read from stdout when copying git's output to another stream
-    max_chunk_size = 1024 * 64
+    max_chunk_size = io.DEFAULT_BUFFER_SIZE
 
     git_exec_name = "git"           # default that should work on linux and windows
-    git_exec_name_win = "git.cmd"   # alternate command name, windows only
 
     # Enables debugging of GitPython's git commands
     GIT_PYTHON_TRACE = os.environ.get("GIT_PYTHON_TRACE", False)
 
-    # value of Windows process creation flag taken from MSDN
-    CREATE_NO_WINDOW = 0x08000000
-    
     # Provide the full path to the git executable. Otherwise it assumes git is in the path
     _git_exec_env_var = "GIT_PYTHON_GIT_EXECUTABLE"
     GIT_PYTHON_GIT_EXECUTABLE = os.environ.get(_git_exec_env_var, git_exec_name)
 
     # If True, a shell will be used when executing git commands.
-    # This should only be desirable on windows, see https://github.com/gitpython-developers/GitPython/pull/126
-    # for more information
+    # This should only be desirable on Windows, see https://github.com/gitpython-developers/GitPython/pull/126
+    # and check `git/test_repo.py:TestRepo.test_untracked_files()` TC for an example where it is required.
     # Override this value using `Git.USE_SHELL = True`
     USE_SHELL = False
 
@@ -315,9 +218,10 @@ class Git(LazyMixin):
 
             # try to kill it
             try:
-                os.kill(proc.pid, 2)   # interrupt signal
+                proc.terminate()
                 proc.wait()    # ensure process goes away
-            except (OSError, WindowsError):
+            except OSError as ex:
+                log.info("Ignored error after process has dies: %r", ex)
                 pass  # ignore error when process already died
             except AttributeError:
                 # try windows
@@ -339,7 +243,7 @@ class Git(LazyMixin):
             if stderr is None:
                 stderr = b''
             stderr = force_bytes(stderr)
-            
+
             status = self.proc.wait()
 
             def read_all_from_possibly_closed_stream(stream):
@@ -447,6 +351,7 @@ class Git(LazyMixin):
             line = self.readline()
             if not line:
                 raise StopIteration
+
             return line
 
         def __del__(self):
@@ -517,6 +422,7 @@ class Git(LazyMixin):
                 kill_after_timeout=None,
                 with_stdout=True,
                 universal_newlines=False,
+                shell=None,
                 **subprocess_kwargs
                 ):
         """Handles executing the command on the shell and consumes and returns
@@ -574,6 +480,9 @@ class Git(LazyMixin):
         :param universal_newlines:
             if True, pipes will be opened as text, and lines are split at
             all known line endings.
+        :param shell:
+            Whether to invoke commands through a shell (see `Popen(..., shell=True)`).
+            It overrides :attr:`USE_SHELL` if it is not `None`.
         :param kill_after_timeout:
             To specify a timeout in seconds for the git command, after which the process
             should be killed. This will have no effect if as_process is set to True. It is
@@ -619,18 +528,18 @@ class Git(LazyMixin):
         env["LC_ALL"] = "C"
         env.update(self._environment)
 
-        if sys.platform == 'win32':
-            cmd_not_found_exception = WindowsError
+        if is_win:
+            cmd_not_found_exception = OSError
             if kill_after_timeout:
-                raise GitCommandError('"kill_after_timeout" feature is not supported on Windows.')
+                raise GitCommandError(command, '"kill_after_timeout" feature is not supported on Windows.')
         else:
             if sys.version_info[0] > 2:
-                cmd_not_found_exception = FileNotFoundError  # NOQA # this is defined, but flake8 doesn't know
+                cmd_not_found_exception = FileNotFoundError  # NOQA # exists, flake8 unknown @UndefinedVariable
             else:
                 cmd_not_found_exception = OSError
         # end handle
 
-        creationflags = self.CREATE_NO_WINDOW if sys.platform == 'win32' else 0
+        log.debug("Popen(%s, cwd=%s, universal_newlines=%s", command, cwd, universal_newlines)
         try:
             proc = Popen(command,
                          env=env,
@@ -639,21 +548,22 @@ class Git(LazyMixin):
                          stdin=istream,
                          stderr=PIPE,
                          stdout=PIPE if with_stdout else open(os.devnull, 'wb'),
-                         shell=self.USE_SHELL,
-                         close_fds=(os.name == 'posix'),  # unsupported on windows
+                         shell=shell is not None and shell or self.USE_SHELL,
+                         close_fds=(is_posix),  # unsupported on windows
                          universal_newlines=universal_newlines,
-                         creationflags=creationflags,
+                         creationflags=PROC_CREATIONFLAGS,
                          **subprocess_kwargs
                          )
         except cmd_not_found_exception as err:
-            raise GitCommandNotFound(str(err))
+            raise GitCommandNotFound(command, err)
 
         if as_process:
             return self.AutoInterrupt(proc, command)
 
         def _kill_process(pid):
             """ Callback method to kill a process. """
-            p = Popen(['ps', '--ppid', str(pid)], stdout=PIPE, creationflags=creationflags)
+            p = Popen(['ps', '--ppid', str(pid)], stdout=PIPE,
+                      creationflags=PROC_CREATIONFLAGS)
             child_pids = []
             for line in p.stdout:
                 if len(line.split()) > 0:
@@ -679,7 +589,7 @@ class Git(LazyMixin):
 
         if kill_after_timeout:
             kill_check = threading.Event()
-            watchdog = threading.Timer(kill_after_timeout, _kill_process, args=(proc.pid, ))
+            watchdog = threading.Timer(kill_after_timeout, _kill_process, args=(proc.pid,))
 
         # Wait for the process to return
         status = 0
@@ -766,10 +676,7 @@ class Git(LazyMixin):
         for key, value in kwargs.items():
             # set value if it is None
             if value is not None:
-                if key in self._environment:
-                    old_env[key] = self._environment[key]
-                else:
-                    old_env[key] = None
+                old_env[key] = self._environment.get(key)
                 self._environment[key] = value
             # remove key from environment if its value is None
             elif key in self._environment:
@@ -885,12 +792,8 @@ class Git(LazyMixin):
         :return: Same as ``execute``"""
         # Handle optional arguments prior to calling transform_kwargs
         # otherwise these'll end up in args, which is bad.
-        _kwargs = dict()
-        for kwarg in execute_kwargs:
-            try:
-                _kwargs[kwarg] = kwargs.pop(kwarg)
-            except KeyError:
-                pass
+        _kwargs = {k: v for k, v in kwargs.items() if k in execute_kwargs}
+        kwargs = {k: v for k, v in kwargs.items() if k not in execute_kwargs}
 
         insert_after_this_arg = kwargs.pop('insert_kwargs_after', None)
 
@@ -910,48 +813,17 @@ class Git(LazyMixin):
             args = ext_args[:index + 1] + opt_args + ext_args[index + 1:]
         # end handle kwargs
 
-        def make_call():
-            call = [self.GIT_PYTHON_GIT_EXECUTABLE]
-
-            # add the git options, the reset to empty
-            # to avoid side_effects
-            call.extend(self._git_options)
-            self._git_options = ()
+        call = [self.GIT_PYTHON_GIT_EXECUTABLE]
 
-            call.extend([dashify(method)])
-            call.extend(args)
-            return call
-        # END utility to recreate call after changes
+        # add the git options, the reset to empty
+        # to avoid side_effects
+        call.extend(self._git_options)
+        self._git_options = ()
 
-        if sys.platform == 'win32':
-            try:
-                try:
-                    return self.execute(make_call(), **_kwargs)
-                except WindowsError:
-                    # did we switch to git.cmd already, or was it changed from default ? permanently fail
-                    if self.GIT_PYTHON_GIT_EXECUTABLE != self.git_exec_name:
-                        raise
-                    # END handle overridden variable
-                    type(self).GIT_PYTHON_GIT_EXECUTABLE = self.git_exec_name_win
+        call.append(dashify(method))
+        call.extend(args)
 
-                    try:
-                        return self.execute(make_call(), **_kwargs)
-                    finally:
-                        import warnings
-                        msg = "WARNING: Automatically switched to use git.cmd as git executable"
-                        msg += ", which reduces performance by ~70%."
-                        msg += "It is recommended to put git.exe into the PATH or to "
-                        msg += "set the %s " % self._git_exec_env_var
-                        msg += "environment variable to the executable's location"
-                        warnings.warn(msg)
-                    # END print of warning
-                # END catch first failure
-            except WindowsError:
-                raise WindowsError("The system cannot find or execute the file at %r" % self.GIT_PYTHON_GIT_EXECUTABLE)
-            # END provide better error message
-        else:
-            return self.execute(make_call(), **_kwargs)
-        # END handle windows default installation
+        return self.execute(call, **_kwargs)
 
     def _parse_object_header(self, header_line):
         """
@@ -1040,6 +912,10 @@ class Git(LazyMixin):
         Currently persistent commands will be interrupted.
 
         :return: self"""
+        for cmd in (self.cat_file_all, self.cat_file_header):
+            if cmd:
+                cmd.__del__()
+
         self.cat_file_all = None
         self.cat_file_header = None
         return self
diff --git a/git/compat.py b/git/compat.py
index b3572474..441a3761 100644
--- a/git/compat.py
+++ b/git/compat.py
@@ -7,15 +7,15 @@
 """utilities to help provide compatibility with python 3"""
 # flake8: noqa
 
+import locale
+import os
 import sys
 
 from gitdb.utils.compat import (
-    PY3,
     xrange,
     MAXSIZE,
     izip,
 )
-
 from gitdb.utils.encoding import (
     string_types,
     text_type,
@@ -23,7 +23,13 @@ from gitdb.utils.encoding import (
     force_text
 )
 
+
+PY3 = sys.version_info[0] >= 3
+is_win = (os.name == 'nt')
+is_posix = (os.name == 'posix')
+is_darwin = (os.name == 'darwin')
 defenc = sys.getdefaultencoding()
+
 if PY3:
     import io
     FileType = io.IOBase
@@ -57,7 +63,28 @@ def safe_decode(s):
         return s
     elif isinstance(s, bytes):
         return s.decode(defenc, 'replace')
-    raise TypeError('Expected bytes or text, but got %r' % (s,))
+    elif s is not None:
+        raise TypeError('Expected bytes or text, but got %r' % (s,))
+
+
+def safe_encode(s):
+    """Safely decodes a binary string to unicode"""
+    if isinstance(s, unicode):
+        return s.encode(defenc)
+    elif isinstance(s, bytes):
+        return s
+    elif s is not None:
+        raise TypeError('Expected bytes or text, but got %r' % (s,))
+
+
+def win_encode(s):
+    """Encode unicodes for process arguments on Windows."""
+    if isinstance(s, unicode):
+        return s.encode(locale.getpreferredencoding(False))
+    elif isinstance(s, bytes):
+        return s
+    elif s is not None:
+        raise TypeError('Expected bytes or text, but got %r' % (s,))
 
 
 def with_metaclass(meta, *bases):
@@ -73,9 +100,19 @@ def with_metaclass(meta, *bases):
             # we set the __metaclass__ attribute explicitly
             if not PY3 and '___metaclass__' not in d:
                 d['__metaclass__'] = meta
-            # end
             return meta(name, bases, d)
-        # end
-    # end metaclass
     return metaclass(meta.__name__ + 'Helper', None, {})
-    # end handle py2
+
+
+## From https://docs.python.org/3.3/howto/pyporting.html
+class UnicodeMixin(object):
+
+    """Mixin class to handle defining the proper __str__/__unicode__
+    methods in Python 2 or 3."""
+
+    if PY3:
+        def __str__(self):
+            return self.__unicode__()
+    else:  # Python 2
+        def __str__(self):
+            return self.__unicode__().encode(defenc)
diff --git a/git/config.py b/git/config.py
index 5bd10975..ad6192ff 100644
--- a/git/config.py
+++ b/git/config.py
@@ -388,23 +388,18 @@ class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser, obje
         while files_to_read:
             file_path = files_to_read.pop(0)
             fp = file_path
-            close_fp = False
+            file_ok = False
 
-            # assume a path if it is not a file-object
-            if not hasattr(fp, "seek"):
+            if hasattr(fp, "seek"):
+                self._read(fp, fp.name)
+            else:
+                # assume a path if it is not a file-object
                 try:
-                    fp = open(file_path, 'rb')
-                    close_fp = True
+                    with open(file_path, 'rb') as fp:
+                        file_ok = True
+                        self._read(fp, fp.name)
                 except IOError:
                     continue
-            # END fp handling
-
-            try:
-                self._read(fp, fp.name)
-            finally:
-                if close_fp:
-                    fp.close()
-            # END read-handling
 
             # Read includes and append those that we didn't handle yet
             # We expect all paths to be normalized and absolute (and will assure that is the case)
@@ -413,7 +408,7 @@ class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser, obje
                     if include_path.startswith('~'):
                         include_path = os.path.expanduser(include_path)
                     if not os.path.isabs(include_path):
-                        if not close_fp:
+                        if not file_ok:
                             continue
                         # end ignore relative paths if we don't know the configuration file path
                         assert os.path.isabs(file_path), "Need absolute paths to be sure our cycle checks will work"
@@ -477,34 +472,25 @@ class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser, obje
         # end
 
         fp = self._file_or_files
-        close_fp = False
 
         # we have a physical file on disk, so get a lock
-        if isinstance(fp, string_types + (FileType, )):
+        is_file_lock = isinstance(fp, string_types + (FileType, ))
+        if is_file_lock:
             self._lock._obtain_lock()
-        # END get lock for physical files
-
-        if not hasattr(fp, "seek"):
-            fp = open(self._file_or_files, "wb")
-            close_fp = True
-        else:
-            fp.seek(0)
-            # make sure we do not overwrite into an existing file
-            if hasattr(fp, 'truncate'):
-                fp.truncate()
-            # END
-        # END handle stream or file
-
-        # WRITE DATA
         try:
-            self._write(fp)
+            if not hasattr(fp, "seek"):
+                with open(self._file_or_files, "wb") as fp:
+                    self._write(fp)
+            else:
+                fp.seek(0)
+                # make sure we do not overwrite into an existing file
+                if hasattr(fp, 'truncate'):
+                    fp.truncate()
+                self._write(fp)
         finally:
-            if close_fp:
-                fp.close()
-        # END data writing
-
-        # we do not release the lock - it will be done automatically once the
-        # instance vanishes
+            # we release the lock - it will not vanish automatically in PY3.5+
+            if is_file_lock:
+                self._lock._release_lock()
 
     def _assure_writable(self, method_name):
         if self.read_only:
diff --git a/git/diff.py b/git/diff.py
index fb8faaf6..35c7ff86 100644
--- a/git/diff.py
+++ b/git/diff.py
@@ -15,6 +15,8 @@ from git.compat import (
     defenc,
     PY3
 )
+from git.cmd import handle_process_output
+from git.util import finalize_process
 
 __all__ = ('Diffable', 'DiffIndex', 'Diff', 'NULL_TREE')
 
@@ -145,10 +147,10 @@ class Diffable(object):
         kwargs['as_process'] = True
         proc = diff_cmd(*self._process_diff_args(args), **kwargs)
 
-        diff_method = Diff._index_from_raw_format
-        if create_patch:
-            diff_method = Diff._index_from_patch_format
-        index = diff_method(self.repo, proc.stdout)
+        diff_method = (Diff._index_from_patch_format
+                       if create_patch
+                       else Diff._index_from_raw_format)
+        index = diff_method(self.repo, proc)
 
         proc.wait()
         return index
@@ -397,13 +399,18 @@ class Diff(object):
         return None
 
     @classmethod
-    def _index_from_patch_format(cls, repo, stream):
+    def _index_from_patch_format(cls, repo, proc):
         """Create a new DiffIndex from the given text which must be in patch format
         :param repo: is the repository we are operating on - it is required
         :param stream: result of 'git diff' as a stream (supporting file protocol)
         :return: git.DiffIndex """
+
+        ## FIXME: Here SLURPING raw, need to re-phrase header-regexes linewise.
+        text = []
+        handle_process_output(proc, text.append, None, finalize_process, decode_streams=False)
+
         # for now, we have to bake the stream
-        text = stream.read()
+        text = b''.join(text)
         index = DiffIndex()
         previous_header = None
         for header in cls.re_header.finditer(text):
@@ -450,17 +457,19 @@ class Diff(object):
         return index
 
     @classmethod
-    def _index_from_raw_format(cls, repo, stream):
+    def _index_from_raw_format(cls, repo, proc):
         """Create a new DiffIndex from the given stream which must be in raw format.
         :return: git.DiffIndex"""
         # handles
         # :100644 100644 687099101... 37c5e30c8... M    .gitignore
+
         index = DiffIndex()
-        for line in stream.readlines():
+
+        def handle_diff_line(line):
             line = line.decode(defenc)
             if not line.startswith(":"):
-                continue
-            # END its not a valid diff line
+                return
+
             meta, _, path = line[1:].partition('\t')
             old_mode, new_mode, a_blob_id, b_blob_id, change_type = meta.split(None, 4)
             path = path.strip()
@@ -489,6 +498,7 @@ class Diff(object):
             diff = Diff(repo, a_path, b_path, a_blob_id, b_blob_id, old_mode, new_mode,
                         new_file, deleted_file, rename_from, rename_to, '', change_type)
             index.append(diff)
-        # END for each line
+
+        handle_process_output(proc, handle_diff_line, None, finalize_process, decode_streams=False)
 
         return index
diff --git a/git/exc.py b/git/exc.py
index 34382ecd..47215c21 100644
--- a/git/exc.py
+++ b/git/exc.py
@@ -6,8 +6,7 @@
 """ Module containing all exceptions thrown througout the git package, """
 
 from gitdb.exc import *     # NOQA
-
-from git.compat import defenc
+from git.compat import UnicodeMixin, safe_decode, string_types
 
 
 class InvalidGitRepositoryError(Exception):
@@ -22,29 +21,57 @@ class NoSuchPathError(OSError):
     """ Thrown if a path could not be access by the system. """
 
 
-class GitCommandNotFound(Exception):
+class CommandError(UnicodeMixin, Exception):
+    """Base class for exceptions thrown at every stage of `Popen()` execution.
+
+    :param command:
+        A non-empty list of argv comprising the command-line.
+    """
+
+    #: A unicode print-format with 2 `%s for `<cmdline>` and the rest,
+    #:  e.g.
+    #:     u"'%s' failed%s"
+    _msg = u"Cmd('%s') failed%s"
+
+    def __init__(self, command, status=None, stderr=None, stdout=None):
+        if not isinstance(command, (tuple, list)):
+            command = command.split()
+        self.command = command
+        self.status = status
+        if status:
+            if isinstance(status, Exception):
+                status = u"%s('%s')" % (type(status).__name__, safe_decode(str(status)))
+            else:
+                try:
+                    status = u'exit code(%s)' % int(status)
+                except:
+                    s = safe_decode(str(status))
+                    status = u"'%s'" % s if isinstance(status, string_types) else s
+
+        self._cmd = safe_decode(command[0])
+        self._cmdline = u' '.join(safe_decode(i) for i in command)
+        self._cause = status and u" due to: %s" % status or "!"
+        self.stdout = stdout and u"\n  stdout: '%s'" % safe_decode(stdout) or ''
+        self.stderr = stderr and u"\n  stderr: '%s'" % safe_decode(stderr) or ''
+
+    def __unicode__(self):
+        return (self._msg + "\n  cmdline: %s%s%s") % (
+            self._cmd, self._cause, self._cmdline, self.stdout, self.stderr)
+
+
+class GitCommandNotFound(CommandError):
     """Thrown if we cannot find the `git` executable in the PATH or at the path given by
     the GIT_PYTHON_GIT_EXECUTABLE environment variable"""
-    pass
+    def __init__(self, command, cause):
+        super(GitCommandNotFound, self).__init__(command, cause)
+        self._msg = u"Cmd('%s') not found%s"
 
 
-class GitCommandError(Exception):
+class GitCommandError(CommandError):
     """ Thrown if execution of the git command fails with non-zero status code. """
 
     def __init__(self, command, status, stderr=None, stdout=None):
-        self.stderr = stderr
-        self.stdout = stdout
-        self.status = status
-        self.command = command
-
-    def __str__(self):
-        ret = "'%s' returned with exit code %i" % \
-              (' '.join(str(i) for i in self.command), self.status)
-        if self.stderr:
-            ret += "\nstderr: '%s'" % self.stderr.decode(defenc)
-        if self.stdout:
-            ret += "\nstdout: '%s'" % self.stdout.decode(defenc)
-        return ret
+        super(GitCommandError, self).__init__(command, status, stderr, stdout)
 
 
 class CheckoutError(Exception):
@@ -81,19 +108,13 @@ class UnmergedEntriesError(CacheError):
     entries in the cache"""
 
 
-class HookExecutionError(Exception):
+class HookExecutionError(CommandError):
     """Thrown if a hook exits with a non-zero exit code. It provides access to the exit code and the string returned
     via standard output"""
 
-    def __init__(self, command, status, stdout, stderr):
-        self.command = command
-        self.status = status
-        self.stdout = stdout
-        self.stderr = stderr
-
-    def __str__(self):
-        return ("'%s' hook returned with exit code %i\nstdout: '%s'\nstderr: '%s'"
-                % (self.command, self.status, self.stdout, self.stderr))
+    def __init__(self, command, status, stderr=None, stdout=None):
+        super(HookExecutionError, self).__init__(command, status, stderr, stdout)
+        self._msg = u"Hook('%s') failed%s"
 
 
 class RepositoryDirtyError(Exception):
diff --git a/git/index/base.py b/git/index/base.py
index 86eda41e..9b6d28ab 100644
--- a/git/index/base.py
+++ b/git/index/base.py
@@ -46,7 +46,8 @@ from git.compat import (
     string_types,
     force_bytes,
     defenc,
-    mviter
+    mviter,
+    is_win
 )
 
 from git.util import (
@@ -136,7 +137,7 @@ class IndexFile(LazyMixin, diff.Diffable, Serializable):
             # which happens during read-tree.
             # In this case, we will just read the memory in directly.
             # Its insanely bad ... I am disappointed !
-            allow_mmap = (os.name != 'nt' or sys.version_info[1] > 5)
+            allow_mmap = (is_win or sys.version_info[1] > 5)
             stream = file_contents_ro(fd, stream=True, allow_mmap=allow_mmap)
 
             try:
@@ -213,8 +214,8 @@ class IndexFile(LazyMixin, diff.Diffable, Serializable):
         self.entries
         lfd = LockedFD(file_path or self._file_path)
         stream = lfd.open(write=True, stream=True)
-        ok = False
 
+        ok = False
         try:
             self._serialize(stream, ignore_extension_data)
             ok = True
@@ -601,14 +602,13 @@ class IndexFile(LazyMixin, diff.Diffable, Serializable):
         stream = None
         if S_ISLNK(st.st_mode):
             # in PY3, readlink is string, but we need bytes. In PY2, it's just OS encoded bytes, we assume UTF-8
-            stream = BytesIO(force_bytes(os.readlink(filepath), encoding=defenc))
+            open_stream = lambda: BytesIO(force_bytes(os.readlink(filepath), encoding=defenc))
         else:
-            stream = open(filepath, 'rb')
-        # END handle stream
-        fprogress(filepath, False, filepath)
-        istream = self.repo.odb.store(IStream(Blob.type, st.st_size, stream))
-        fprogress(filepath, True, filepath)
-        stream.close()
+            open_stream = lambda: open(filepath, 'rb')
+        with open_stream() as stream:
+            fprogress(filepath, False, filepath)
+            istream = self.repo.odb.store(IStream(Blob.type, st.st_size, stream))
+            fprogress(filepath, True, filepath)
         return BaseIndexEntry((stat_mode_to_index_mode(st.st_mode),
                                istream.binsha, 0, to_native_path_linux(filepath)))
 
@@ -1059,7 +1059,7 @@ class IndexFile(LazyMixin, diff.Diffable, Serializable):
                 # END for each possible ending
             # END for each line
             if unknown_lines:
-                raise GitCommandError(("git-checkout-index", ), 128, stderr)
+                raise GitCommandError(("git-checkout-index",), 128, stderr)
             if failed_files:
                 valid_files = list(set(iter_checked_out_files) - set(failed_files))
                 raise CheckoutError(
@@ -1090,6 +1090,7 @@ class IndexFile(LazyMixin, diff.Diffable, Serializable):
             kwargs['as_process'] = True
             kwargs['istream'] = subprocess.PIPE
             proc = self.repo.git.checkout_index(args, **kwargs)
+            # FIXME: Reading from GIL!
             make_exc = lambda: GitCommandError(("git-checkout-index",) + tuple(args), 128, proc.stderr.read())
             checked_out_files = list()
 
diff --git a/git/index/fun.py b/git/index/fun.py
index 4dd32b19..74ac929e 100644
--- a/git/index/fun.py
+++ b/git/index/fun.py
@@ -14,7 +14,8 @@ from io import BytesIO
 import os
 import subprocess
 
-from git.util import IndexFileSHA1Writer
+from git.util import IndexFileSHA1Writer, finalize_process
+from git.cmd import PROC_CREATIONFLAGS, handle_process_output
 from git.exc import (
     UnmergedEntriesError,
     HookExecutionError
@@ -40,9 +41,13 @@ from .util import (
 from gitdb.base import IStream
 from gitdb.typ import str_tree_type
 from git.compat import (
+    PY3,
     defenc,
     force_text,
-    force_bytes
+    force_bytes,
+    is_posix,
+    safe_encode,
+    safe_decode,
 )
 
 S_IFGITLINK = S_IFLNK | S_IFDIR     # a submodule
@@ -67,22 +72,28 @@ def run_commit_hook(name, index):
         return
 
     env = os.environ.copy()
-    env['GIT_INDEX_FILE'] = index.path
+    env['GIT_INDEX_FILE'] = safe_decode(index.path) if PY3 else safe_encode(index.path)
     env['GIT_EDITOR'] = ':'
-    cmd = subprocess.Popen(hp,
-                           env=env,
-                           stdout=subprocess.PIPE,
-                           stderr=subprocess.PIPE,
-                           cwd=index.repo.working_dir,
-                           close_fds=(os.name == 'posix'))
-    stdout, stderr = cmd.communicate()
-    cmd.stdout.close()
-    cmd.stderr.close()
-
-    if cmd.returncode != 0:
-        stdout = force_text(stdout, defenc)
-        stderr = force_text(stderr, defenc)
-        raise HookExecutionError(hp, cmd.returncode, stdout, stderr)
+    try:
+        cmd = subprocess.Popen(hp,
+                               env=env,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE,
+                               cwd=index.repo.working_dir,
+                               close_fds=is_posix,
+                               creationflags=PROC_CREATIONFLAGS,)
+    except Exception as ex:
+        raise HookExecutionError(hp, ex)
+    else:
+        stdout = []
+        stderr = []
+        handle_process_output(cmd, stdout.append, stderr.append, finalize_process)
+        stdout = ''.join(stdout)
+        stderr = ''.join(stderr)
+        if cmd.returncode != 0:
+            stdout = force_text(stdout, defenc)
+            stderr = force_text(stderr, defenc)
+            raise HookExecutionError(hp, cmd.returncode, stdout, stderr)
     # end handle return code
 
 
diff --git a/git/index/util.py b/git/index/util.py
index 171bd8fc..0340500c 100644
--- a/git/index/util.py
+++ b/git/index/util.py
@@ -2,6 +2,7 @@
 import struct
 import tempfile
 import os
+from git.compat import is_win
 
 __all__ = ('TemporaryFileSwap', 'post_clear_cache', 'default_index', 'git_working_dir')
 
@@ -29,7 +30,7 @@ class TemporaryFileSwap(object):
 
     def __del__(self):
         if os.path.isfile(self.tmp_file_path):
-            if os.name == 'nt' and os.path.exists(self.file_path):
+            if is_win and os.path.exists(self.file_path):
                 os.remove(self.file_path)
             os.rename(self.tmp_file_path, self.file_path)
         # END temp file exists
diff --git a/git/objects/submodule/base.py b/git/objects/submodule/base.py
index eea091f8..c6c6d699 100644
--- a/git/objects/submodule/base.py
+++ b/git/objects/submodule/base.py
@@ -29,7 +29,8 @@ from git.exc import (
 )
 from git.compat import (
     string_types,
-    defenc
+    defenc,
+    is_win,
 )
 
 import stat
@@ -289,14 +290,16 @@ class Submodule(util.IndexObject, Iterable, Traversable):
         """
         git_file = os.path.join(working_tree_dir, '.git')
         rela_path = os.path.relpath(module_abspath, start=working_tree_dir)
-        fp = open(git_file, 'wb')
-        fp.write(("gitdir: %s" % rela_path).encode(defenc))
-        fp.close()
+        if is_win:
+            if os.path.isfile(git_file):
+                os.remove(git_file)
+        with open(git_file, 'wb') as fp:
+            fp.write(("gitdir: %s" % rela_path).encode(defenc))
 
-        writer = GitConfigParser(os.path.join(module_abspath, 'config'), read_only=False, merge_includes=False)
-        writer.set_value('core', 'worktree',
-                         to_native_path_linux(os.path.relpath(working_tree_dir, start=module_abspath)))
-        writer.release()
+        with GitConfigParser(os.path.join(module_abspath, 'config'),
+                             read_only=False, merge_includes=False) as writer:
+            writer.set_value('core', 'worktree',
+                             to_native_path_linux(os.path.relpath(working_tree_dir, start=module_abspath)))
 
     #{ Edit Interface
 
@@ -848,13 +851,17 @@ class Submodule(util.IndexObject, Iterable, Traversable):
 
                 # finally delete our own submodule
                 if not dry_run:
+                    self._clear_cache()
                     wtd = mod.working_tree_dir
                     del(mod)        # release file-handles (windows)
+                    import gc
+                    gc.collect()
                     rmtree(wtd)
                 # END delete tree if possible
             # END handle force
 
             if not dry_run and os.path.isdir(git_dir):
+                self._clear_cache()
                 rmtree(git_dir)
             # end handle separate bare repository
         # END handle module deletion
diff --git a/git/refs/symbolic.py b/git/refs/symbolic.py
index ec2944c6..894b26d5 100644
--- a/git/refs/symbolic.py
+++ b/git/refs/symbolic.py
@@ -134,9 +134,8 @@ class SymbolicReference(object):
         point to, or None"""
         tokens = None
         try:
-            fp = open(join(repo.git_dir, ref_path), 'rt')
-            value = fp.read().rstrip()
-            fp.close()
+            with open(join(repo.git_dir, ref_path), 'rt') as fp:
+                value = fp.read().rstrip()
             # Don't only split on spaces, but on whitespace, which allows to parse lines like
             # 60b64ef992065e2600bfef6187a97f92398a9144                branch 'master' of git-server:/path/to/repo
             tokens = value.split()
@@ -313,13 +312,17 @@ class SymbolicReference(object):
 
         lfd = LockedFD(fpath)
         fd = lfd.open(write=True, stream=True)
-        fd.write(write_value.encode('ascii') + b'\n')
-        lfd.commit()
-
+        ok = True
+        try:
+            fd.write(write_value.encode('ascii') + b'\n')
+            lfd.commit()
+            ok = True
+        finally:
+            if not ok:
+                lfd.rollback()
         # Adjust the reflog
         if logmsg is not None:
             self.log_append(oldbinsha, logmsg)
-        # END handle reflog
 
         return self
 
@@ -422,40 +425,36 @@ class SymbolicReference(object):
             # check packed refs
             pack_file_path = cls._get_packed_refs_path(repo)
             try:
-                reader = open(pack_file_path, 'rb')
-            except (OSError, IOError):
-                pass  # it didnt exist at all
-            else:
-                new_lines = list()
-                made_change = False
-                dropped_last_line = False
-                for line in reader:
-                    # keep line if it is a comment or if the ref to delete is not
-                    # in the line
-                    # If we deleted the last line and this one is a tag-reference object,
-                    # we drop it as well
-                    line = line.decode(defenc)
-                    if (line.startswith('#') or full_ref_path not in line) and \
-                            (not dropped_last_line or dropped_last_line and not line.startswith('^')):
-                        new_lines.append(line)
-                        dropped_last_line = False
-                        continue
-                    # END skip comments and lines without our path
-
-                    # drop this line
-                    made_change = True
-                    dropped_last_line = True
-                # END for each line in packed refs
-                reader.close()
+                with open(pack_file_path, 'rb') as reader:
+                    new_lines = list()
+                    made_change = False
+                    dropped_last_line = False
+                    for line in reader:
+                        # keep line if it is a comment or if the ref to delete is not
+                        # in the line
+                        # If we deleted the last line and this one is a tag-reference object,
+                        # we drop it as well
+                        line = line.decode(defenc)
+                        if (line.startswith('#') or full_ref_path not in line) and \
+                                (not dropped_last_line or dropped_last_line and not line.startswith('^')):
+                            new_lines.append(line)
+                            dropped_last_line = False
+                            continue
+                        # END skip comments and lines without our path
+
+                        # drop this line
+                        made_change = True
+                        dropped_last_line = True
 
                 # write the new lines
                 if made_change:
                     # write-binary is required, otherwise windows will
                     # open the file in text mode and change LF to CRLF !
-                    open(pack_file_path, 'wb').writelines(l.encode(defenc) for l in new_lines)
-                # END write out file
-            # END open exception handling
-        # END handle deletion
+                    with open(pack_file_path, 'wb') as fd:
+                        fd.writelines(l.encode(defenc) for l in new_lines)
+
+            except (OSError, IOError):
+                pass  # it didnt exist at all
 
         # delete the reflog
         reflog_path = RefLog.path(cls(repo, full_ref_path))
@@ -484,7 +483,8 @@ class SymbolicReference(object):
                 target_data = target.path
             if not resolve:
                 target_data = "ref: " + target_data
-            existing_data = open(abs_ref_path, 'rb').read().decode(defenc).strip()
+            with open(abs_ref_path, 'rb') as fd:
+                existing_data = fd.read().decode(defenc).strip()
             if existing_data != target_data:
                 raise OSError("Reference at %r does already exist, pointing to %r, requested was %r" %
                               (full_ref_path, existing_data, target_data))
@@ -549,7 +549,11 @@ class SymbolicReference(object):
         if isfile(new_abs_path):
             if not force:
                 # if they point to the same file, its not an error
-                if open(new_abs_path, 'rb').read().strip() != open(cur_abs_path, 'rb').read().strip():
+                with open(new_abs_path, 'rb') as fd1:
+                    f1 = fd1.read().strip()
+                with open(cur_abs_path, 'rb') as fd2:
+                    f2 = fd2.read().strip()
+                if f1 != f2:
                     raise OSError("File at path %r already exists" % new_abs_path)
                 # else: we could remove ourselves and use the otherone, but
                 # but clarity we just continue as usual
diff --git a/git/remote.py b/git/remote.py
index 4a8a5ee9..c2ffcc1a 100644
--- a/git/remote.py
+++ b/git/remote.py
@@ -6,7 +6,6 @@
 
 # Module implementing a remote object allowing easy access to git remotes
 import re
-import os
 
 from .config import (
     SectionConstraint,
@@ -32,7 +31,7 @@ from git.util import (
 )
 from git.cmd import handle_process_output
 from gitdb.util import join
-from git.compat import (defenc, force_text)
+from git.compat import (defenc, force_text, is_win)
 import logging
 
 log = logging.getLogger('git.remote')
@@ -113,7 +112,7 @@ class PushInfo(object):
         self._remote = remote
         self._old_commit_sha = old_commit
         self.summary = summary
-        
+
     @property
     def old_commit(self):
         return self._old_commit_sha and self._remote.repo.commit(self._old_commit_sha) or None
@@ -377,7 +376,7 @@ class Remote(LazyMixin, Iterable):
         self.repo = repo
         self.name = name
 
-        if os.name == 'nt':
+        if is_win:
             # some oddity: on windows, python 2.5, it for some reason does not realize
             # that it has the config_writer property, but instead calls __getattr__
             # which will not yield the expected results. 'pinging' the members
@@ -635,13 +634,12 @@ class Remote(LazyMixin, Iterable):
         # end
         if progress.error_lines():
             stderr_text = '\n'.join(progress.error_lines())
-            
+
         finalize_process(proc, stderr=stderr_text)
 
         # read head information
-        fp = open(join(self.repo.git_dir, 'FETCH_HEAD'), 'rb')
-        fetch_head_info = [l.decode(defenc) for l in fp.readlines()]
-        fp.close()
+        with open(join(self.repo.git_dir, 'FETCH_HEAD'), 'rb') as fp:
+            fetch_head_info = [l.decode(defenc) for l in fp.readlines()]
 
         l_fil = len(fetch_info_lines)
         l_fhi = len(fetch_head_info)
@@ -657,7 +655,7 @@ class Remote(LazyMixin, Iterable):
                 fetch_info_lines = fetch_info_lines[:l_fhi]
             # end truncate correct list
         # end sanity check + sanitization
-        
+
         output.extend(FetchInfo._from_line(self.repo, err_line, fetch_line)
                       for err_line, fetch_line in zip(fetch_info_lines, fetch_head_info))
         return output
@@ -682,7 +680,7 @@ class Remote(LazyMixin, Iterable):
         # END for each line
 
         try:
-            handle_process_output(proc, stdout_handler, progress_handler, finalize_process)
+            handle_process_output(proc, stdout_handler, progress_handler, finalize_process, decode_streams=False)
         except Exception:
             if len(output) == 0:
                 raise
@@ -769,17 +767,17 @@ class Remote(LazyMixin, Iterable):
         :param refspec: see 'fetch' method
         :param progress:
             Can take one of many value types:
-            
+
             * None to discard progress information
             * A function (callable) that is called with the progress infomation.
-            
+
               Signature: ``progress(op_code, cur_count, max_count=None, message='')``.
-              
+
              `Click here <http://goo.gl/NPa7st>`_ for a description of all arguments
               given to the function.
             * An instance of a class derived from ``git.RemoteProgress`` that
               overrides the ``update()`` function.
-              
+
         :note: No further progress information is returned after push returns.
         :param kwargs: Additional arguments to be passed to git-push
         :return:
diff --git a/git/repo/base.py b/git/repo/base.py
index 0e46ee67..947d77d2 100644
--- a/git/repo/base.py
+++ b/git/repo/base.py
@@ -56,6 +56,7 @@ from git.compat import (
     PY3,
     safe_decode,
     range,
+    is_win,
 )
 
 import os
@@ -71,7 +72,7 @@ if sys.version_info[:2] < (2, 5):     # python 2.4 compatiblity
 BlameEntry = namedtuple('BlameEntry', ['commit', 'linenos', 'orig_path', 'orig_linenos'])
 
 
-__all__ = ('Repo', )
+__all__ = ('Repo',)
 
 
 def _expand_path(p):
@@ -209,11 +210,13 @@ class Repo(object):
     # Description property
     def _get_description(self):
         filename = join(self.git_dir, 'description')
-        return open(filename, 'rb').read().rstrip().decode(defenc)
+        with open(filename, 'rb') as fp:
+            return fp.read().rstrip().decode(defenc)
 
     def _set_description(self, descr):
         filename = join(self.git_dir, 'description')
-        open(filename, 'wb').write((descr + '\n').encode(defenc))
+        with open(filename, 'wb') as fp:
+            fp.write((descr + '\n').encode(defenc))
 
     description = property(_get_description, _set_description,
                            doc="the project's description")
@@ -369,7 +372,7 @@ class Repo(object):
     def _get_config_path(self, config_level):
         # we do not support an absolute path of the gitconfig on windows ,
         # use the global config instead
-        if sys.platform == "win32" and config_level == "system":
+        if is_win and config_level == "system":
             config_level = "global"
 
         if config_level == "system":
@@ -547,11 +550,8 @@ class Repo(object):
         alternates_path = join(self.git_dir, 'objects', 'info', 'alternates')
 
         if os.path.exists(alternates_path):
-            try:
-                f = open(alternates_path, 'rb')
+            with open(alternates_path, 'rb') as f:
                 alts = f.read().decode(defenc)
-            finally:
-                f.close()
             return alts.strip().splitlines()
         else:
             return list()
@@ -572,13 +572,8 @@ class Repo(object):
             if isfile(alternates_path):
                 os.remove(alternates_path)
         else:
-            try:
-                f = open(alternates_path, 'wb')
+            with open(alternates_path, 'wb') as f:
                 f.write("\n".join(alts).encode(defenc))
-            finally:
-                f.close()
-            # END file handling
-        # END alts handling
 
     alternates = property(_get_alternates, _set_alternates,
                           doc="Retrieve a list of alternates paths or set a list paths to be used as alternates")
@@ -883,7 +878,7 @@ class Repo(object):
         prev_cwd = None
         prev_path = None
         odbt = kwargs.pop('odbt', odb_default_type)
-        if os.name == 'nt':
+        if is_win:
             if '~' in path:
                 raise OSError("Git cannot handle the ~ character in path %r correctly" % path)
 
@@ -904,12 +899,8 @@ class Repo(object):
         try:
             proc = git.clone(url, path, with_extended_output=True, as_process=True,
                              v=True, **add_progress(kwargs, git, progress))
-            if progress:
-                handle_process_output(proc, None, progress.new_message_handler(), finalize_process)
-            else:
-                (stdout, stderr) = proc.communicate()
-                finalize_process(proc, stderr=stderr)
-            # end handle progress
+            progress_handler = progress and progress.new_message_handler() or None
+            handle_process_output(proc, None, progress_handler, finalize_process)
         finally:
             if prev_cwd is not None:
                 os.chdir(prev_cwd)
diff --git a/git/repo/fun.py b/git/repo/fun.py
index 6b06663a..0483eaa9 100644
--- a/git/repo/fun.py
+++ b/git/repo/fun.py
@@ -25,8 +25,8 @@ __all__ = ('rev_parse', 'is_git_dir', 'touch', 'find_git_dir', 'name_to_object',
 
 
 def touch(filename):
-    fp = open(filename, "ab")
-    fp.close()
+    with open(filename, "ab"):
+        pass
     return filename
 
 
diff --git a/git/test/fixtures/cat_file.py b/git/test/fixtures/cat_file.py
index 2f1b915a..5480e628 100644
--- a/git/test/fixtures/cat_file.py
+++ b/git/test/fixtures/cat_file.py
@@ -1,5 +1,6 @@
 import sys
 
-for line in open(sys.argv[1]).readlines():
-    sys.stdout.write(line)
-    sys.stderr.write(line)
+with open(sys.argv[1]) as fd:
+    for line in fd.readlines():
+        sys.stdout.write(line)
+        sys.stderr.write(line)
diff --git a/git/test/lib/asserts.py b/git/test/lib/asserts.py
index 60a888b3..9edc49e0 100644
--- a/git/test/lib/asserts.py
+++ b/git/test/lib/asserts.py
@@ -16,7 +16,10 @@ from nose.tools import (
     assert_false
 )
 
-from mock import patch
+try:
+    from unittest.mock import patch
+except ImportError:
+    from mock import patch
 
 __all__ = ['assert_instance_of', 'assert_not_instance_of',
            'assert_none', 'assert_not_none',
diff --git a/git/test/lib/helper.py b/git/test/lib/helper.py
index 8be2881c..a85ac2fd 100644
--- a/git/test/lib/helper.py
+++ b/git/test/lib/helper.py
@@ -4,16 +4,18 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 from __future__ import print_function
+
 import os
-import sys
 from unittest import TestCase
 import time
 import tempfile
-import shutil
 import io
+import logging
 
 from git import Repo, Remote, GitCommandError, Git
-from git.compat import string_types
+from git.util import rmtree
+from git.compat import string_types, is_win
+import textwrap
 
 osp = os.path.dirname
 
@@ -22,9 +24,12 @@ GIT_DAEMON_PORT = os.environ.get("GIT_PYTHON_TEST_GIT_DAEMON_PORT", "9418")
 
 __all__ = (
     'fixture_path', 'fixture', 'absolute_project_path', 'StringProcessAdapter',
-    'with_rw_repo', 'with_rw_and_rw_remote_repo', 'TestBase', 'TestCase', 'GIT_REPO', 'GIT_DAEMON_PORT'
+    'with_rw_directory', 'with_rw_repo', 'with_rw_and_rw_remote_repo', 'TestBase', 'TestCase',
+    'GIT_REPO', 'GIT_DAEMON_PORT'
 )
 
+log = logging.getLogger('git.util')
+
 #{ Routines
 
 
@@ -34,7 +39,8 @@ def fixture_path(name):
 
 
 def fixture(name):
-    return open(fixture_path(name), 'rb').read()
+    with open(fixture_path(name), 'rb') as fd:
+        return fd.read()
 
 
 def absolute_project_path():
@@ -71,21 +77,36 @@ def _mktemp(*args):
     prefixing /private/ will lead to incorrect paths on OSX."""
     tdir = tempfile.mktemp(*args)
     # See :note: above to learn why this is comented out.
-    # if sys.platform == 'darwin':
+    # if is_darwin:
     #     tdir = '/private' + tdir
     return tdir
 
 
-def _rmtree_onerror(osremove, fullpath, exec_info):
-    """
-    Handle the case on windows that read-only files cannot be deleted by
-    os.remove by setting it to mode 777, then retry deletion.
-    """
-    if os.name != 'nt' or osremove is not os.remove:
-        raise
+def with_rw_directory(func):
+    """Create a temporary directory which can be written to, remove it if the
+    test succeeds, but leave it otherwise to aid additional debugging"""
 
-    os.chmod(fullpath, 0o777)
-    os.remove(fullpath)
+    def wrapper(self):
+        path = tempfile.mktemp(prefix=func.__name__)
+        os.mkdir(path)
+        keep = False
+        try:
+            try:
+                return func(self, path)
+            except Exception:
+                log.info.write("Test %s.%s failed, output is at %r\n",
+                               type(self).__name__, func.__name__, path)
+                keep = True
+                raise
+        finally:
+            # Need to collect here to be sure all handles have been closed. It appears
+            # a windows-only issue. In fact things should be deleted, as well as
+            # memory maps closed, once objects go out of scope. For some reason
+            # though this is not the case here unless we collect explicitly.
+            import gc
+            gc.collect()
+            if not keep:
+                rmtree(path)
 
 
 def with_rw_repo(working_tree_ref, bare=False):
@@ -120,14 +141,17 @@ def with_rw_repo(working_tree_ref, bare=False):
                 try:
                     return func(self, rw_repo)
                 except:
-                    print("Keeping repo after failure: %s" % repo_dir, file=sys.stderr)
+                    log.info("Keeping repo after failure: %s", repo_dir)
                     repo_dir = None
                     raise
             finally:
                 os.chdir(prev_cwd)
                 rw_repo.git.clear_cache()
+                rw_repo = None
+                import gc
+                gc.collect()
                 if repo_dir is not None:
-                    shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
+                    rmtree(repo_dir)
                 # END rm test repo if possible
             # END cleanup
         # END rw repo creator
@@ -137,6 +161,28 @@ def with_rw_repo(working_tree_ref, bare=False):
     return argument_passer
 
 
+def launch_git_daemon(temp_dir, ip, port):
+    if is_win:
+        ## On MINGW-git, daemon exists in .\Git\mingw64\libexec\git-core\,
+        #  but if invoked as 'git daemon', it detaches from parent `git` cmd,
+        #  and then CANNOT DIE!
+        #  So, invoke it as a single command.
+        ## Cygwin-git has no daemon.
+        #
+        daemon_cmd = ['git-daemon', temp_dir,
+                      '--enable=receive-pack',
+                      '--listen=%s' % ip,
+                      '--port=%s' % port]
+        gd = Git().execute(daemon_cmd, as_process=True)
+    else:
+        gd = Git().daemon(temp_dir,
+                          enable='receive-pack',
+                          listen=ip,
+                          port=port,
+                          as_process=True)
+    return gd
+
+
 def with_rw_and_rw_remote_repo(working_tree_ref):
     """
     Same as with_rw_repo, but also provides a writable remote repository from which the
@@ -164,6 +210,7 @@ def with_rw_and_rw_remote_repo(working_tree_ref):
     assert isinstance(working_tree_ref, string_types), "Decorator requires ref name for working tree checkout"
 
     def argument_passer(func):
+
         def remote_repo_creator(self):
             remote_repo_dir = _mktemp("remote_repo_%s" % func.__name__)
             repo_dir = _mktemp("remote_clone_non_bare_repo")
@@ -199,62 +246,74 @@ def with_rw_and_rw_remote_repo(working_tree_ref):
             d_remote.config_writer.set('url', remote_repo_url)
 
             temp_dir = osp(_mktemp())
-            # On windows, this will fail ... we deal with failures anyway and default to telling the user to do it
+            gd = launch_git_daemon(temp_dir, '127.0.0.1', GIT_DAEMON_PORT)
             try:
-                gd = Git().daemon(temp_dir, enable='receive-pack', listen='127.0.0.1', port=GIT_DAEMON_PORT,
-                                  as_process=True)
                 # yes, I know ... fortunately, this is always going to work if sleep time is just large enough
                 time.sleep(0.5)
-            except Exception:
-                gd = None
             # end
 
-            # try to list remotes to diagnoes whether the server is up
-            try:
-                rw_repo.git.ls_remote(d_remote)
-            except GitCommandError as e:
-                # We assume in good faith that we didn't start the daemon - but make sure we kill it anyway
-                # Of course we expect it to work here already, but maybe there are timing constraints
-                # on some platforms ?
-                if gd is not None:
-                    os.kill(gd.proc.pid, 15)
-                print(str(e))
-                if os.name == 'nt':
-                    msg = "git-daemon needs to run this test, but windows does not have one. "
-                    msg += 'Otherwise, run: git-daemon "%s"' % temp_dir
-                    raise AssertionError(msg)
-                else:
-                    msg = 'Please start a git-daemon to run this test, execute: git daemon --enable=receive-pack "%s"'
-                    msg += 'You can also run the daemon on a different port by passing --port=<port>'
-                    msg += 'and setting the environment variable GIT_PYTHON_TEST_GIT_DAEMON_PORT to <port>'
-                    msg %= temp_dir
-                    raise AssertionError(msg)
-                # END make assertion
-            # END catch ls remote error
-
-            # adjust working dir
-            prev_cwd = os.getcwd()
-            os.chdir(rw_repo.working_dir)
-            try:
+                # try to list remotes to diagnoes whether the server is up
+                try:
+                    rw_repo.git.ls_remote(d_remote)
+                except GitCommandError as e:
+                    # We assume in good faith that we didn't start the daemon - but make sure we kill it anyway
+                    # Of course we expect it to work here already, but maybe there are timing constraints
+                    # on some platforms ?
+                    try:
+                        gd.proc.terminate()
+                    except Exception as ex:
+                        log.debug("Ignoring %r while terminating proc after %r.", ex, e)
+                    log.warning('git(%s) ls-remote failed due to:%s',
+                                rw_repo.git_dir, e)
+                    if is_win:
+                        msg = textwrap.dedent("""
+                        MINGW yet has problems with paths, and `git-daemon.exe` must be in PATH
+                        (look into .\Git\mingw64\libexec\git-core\);
+                        CYGWIN has no daemon, but if one exists, it gets along fine (has also paths problems)
+                        Anyhow, alternatively try starting `git-daemon` manually:""")
+                    else:
+                        msg = "Please try starting `git-daemon` manually:"
+
+                    msg += textwrap.dedent("""
+                        git daemon --enable=receive-pack '%s'
+                    You can also run the daemon on a different port by passing --port=<port>"
+                    and setting the environment variable GIT_PYTHON_TEST_GIT_DAEMON_PORT to <port>
+                    """ % temp_dir)
+                    from nose import SkipTest
+                    raise SkipTest(msg) if is_win else AssertionError(msg)
+                    # END make assertion
+                # END catch ls remote error
+
+                # adjust working dir
+                prev_cwd = os.getcwd()
+                os.chdir(rw_repo.working_dir)
+
                 try:
                     return func(self, rw_repo, rw_remote_repo)
                 except:
-                    print("Keeping repos after failure: repo_dir = %s, remote_repo_dir = %s"
-                          % (repo_dir, remote_repo_dir), file=sys.stderr)
+                    log.info("Keeping repos after failure: repo_dir = %s, remote_repo_dir = %s",
+                             repo_dir, remote_repo_dir)
                     repo_dir = remote_repo_dir = None
                     raise
+                finally:
+                    os.chdir(prev_cwd)
+
             finally:
-                # gd.proc.kill() ... no idea why that doesn't work
-                if gd is not None:
-                    os.kill(gd.proc.pid, 15)
+                try:
+                    gd.proc.kill()
+                except:
+                    ## Either it has died (and we're here), or it won't die, again here...
+                    pass
 
-                os.chdir(prev_cwd)
                 rw_repo.git.clear_cache()
                 rw_remote_repo.git.clear_cache()
+                rw_repo = rw_remote_repo = None
+                import gc
+                gc.collect()
                 if repo_dir:
-                    shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
+                    rmtree(repo_dir)
                 if remote_repo_dir:
-                    shutil.rmtree(remote_repo_dir, onerror=_rmtree_onerror)
+                    rmtree(remote_repo_dir)
 
                 if gd is not None:
                     gd.proc.wait()
@@ -299,6 +358,8 @@ class TestBase(TestCase):
         Dynamically add a read-only repository to our actual type. This way
         each test type has its own repository
         """
+        import gc
+        gc.collect()
         cls.rorepo = Repo(GIT_REPO)
 
     @classmethod
@@ -313,7 +374,6 @@ class TestBase(TestCase):
         """
         repo = repo or self.rorepo
         abs_path = os.path.join(repo.working_tree_dir, rela_path)
-        fp = open(abs_path, "w")
-        fp.write(data)
-        fp.close()
+        with open(abs_path, "w") as fp:
+            fp.write(data)
         return abs_path
diff --git a/git/test/performance/lib.py b/git/test/performance/lib.py
index bb3f7a99..eebbfd76 100644
--- a/git/test/performance/lib.py
+++ b/git/test/performance/lib.py
@@ -4,7 +4,6 @@ from git.test.lib import (
     TestBase
 )
 from gitdb.test.lib import skip_on_travis_ci
-import shutil
 import tempfile
 import logging
 
@@ -16,6 +15,7 @@ from git.db import (
 from git import (
     Repo
 )
+from git.util import rmtree
 
 #{ Invvariants
 k_env_git_repo = "GIT_PYTHON_TEST_GIT_REPO_BASE"
@@ -86,7 +86,7 @@ class TestBigRepoRW(TestBigRepoR):
     def tearDown(self):
         super(TestBigRepoRW, self).tearDown()
         if self.gitrwrepo is not None:
-            shutil.rmtree(self.gitrwrepo.working_dir)
+            rmtree(self.gitrwrepo.working_dir)
             self.gitrwrepo.git.clear_cache()
         self.gitrwrepo = None
         self.puregitrwrepo.git.clear_cache()
diff --git a/git/test/performance/test_commit.py b/git/test/performance/test_commit.py
index b59c747e..c60dc2fc 100644
--- a/git/test/performance/test_commit.py
+++ b/git/test/performance/test_commit.py
@@ -17,6 +17,10 @@ from git.test.test_commit import assert_commit_serialization
 
 class TestPerformance(TestBigRepoRW):
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     # ref with about 100 commits in its history
     ref_100 = '0.1.6'
 
diff --git a/git/test/performance/test_streams.py b/git/test/performance/test_streams.py
index 4b1738cd..8194547c 100644
--- a/git/test/performance/test_streams.py
+++ b/git/test/performance/test_streams.py
@@ -87,6 +87,9 @@ class TestObjDBPerformance(TestBigRepoR):
                   % (size_kib, desc, cs_kib, elapsed_readchunks, size_kib / elapsed_readchunks), file=sys.stderr)
 
             # del db file so git has something to do
+            ostream = None
+            import gc
+            gc.collect()
             os.remove(db_file)
 
             # VS. CGIT
diff --git a/git/test/test_base.py b/git/test/test_base.py
index 7b71a77e..e5e8f173 100644
--- a/git/test/test_base.py
+++ b/git/test/test_base.py
@@ -7,6 +7,7 @@
 import os
 import sys
 import tempfile
+from unittest import skipIf
 
 import git.objects.base as base
 from git.test.lib import (
@@ -23,10 +24,15 @@ from git import (
 )
 from git.objects.util import get_object_type_by_name
 from gitdb.util import hex_to_bin
+from git.compat import is_win
 
 
 class TestBase(TestBase):
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     type_tuples = (("blob", "8741fc1d09d61f02ffd8cded15ff603eff1ec070", "blob.py"),
                    ("tree", "3a6a5e3eeed3723c09f1ef0399f81ed6b8d82e79", "directory"),
                    ("commit", "4251bd59fb8e11e40c40548cba38180a9536118c", None),
@@ -71,13 +77,11 @@ class TestBase(TestBase):
             assert data
 
             tmpfilename = tempfile.mktemp(suffix='test-stream')
-            tmpfile = open(tmpfilename, 'wb+')
-            assert item == item.stream_data(tmpfile)
-            tmpfile.seek(0)
-            assert tmpfile.read() == data
-            tmpfile.close()
+            with open(tmpfilename, 'wb+') as tmpfile:
+                assert item == item.stream_data(tmpfile)
+                tmpfile.seek(0)
+                assert tmpfile.read() == data
             os.remove(tmpfilename)
-            # END stream to file directly
         # END for each object type to create
 
         # each has a unique sha
@@ -112,6 +116,8 @@ class TestBase(TestBase):
         assert rw_remote_repo.config_reader("repository").getboolean("core", "bare")
         assert os.path.isdir(os.path.join(rw_repo.working_tree_dir, 'lib'))
 
+    @skipIf(sys.version_info < (3,) and is_win,
+            "Unicode woes, see https://github.com/gitpython-developers/GitPython/pull/519")
     @with_rw_repo('0.1.6')
     def test_add_unicode(self, rw_repo):
         filename = u"שלום.txt"
@@ -125,9 +131,10 @@ class TestBase(TestBase):
             from nose import SkipTest
             raise SkipTest("Environment doesn't support unicode filenames")
 
-        open(file_path, "wb").write(b'something')
+        with open(file_path, "wb") as fp:
+            fp.write(b'something')
 
-        if os.name == 'nt':
+        if is_win:
             # on windows, there is no way this works, see images on
             # https://github.com/gitpython-developers/GitPython/issues/147#issuecomment-68881897
             # Therefore, it must be added using the python implementation
diff --git a/git/test/test_commit.py b/git/test/test_commit.py
index c0599503..66d988a3 100644
--- a/git/test/test_commit.py
+++ b/git/test/test_commit.py
@@ -19,7 +19,7 @@ from git import (
     Actor,
 )
 from gitdb import IStream
-from gitdb.test.lib import with_rw_directory
+from git.test.lib import with_rw_directory
 from git.compat import (
     string_types,
     text_type
@@ -34,7 +34,11 @@ import re
 import os
 from datetime import datetime
 from git.objects.util import tzoffset, utc
-from mock import Mock
+
+try:
+    from unittest.mock import Mock
+except ImportError:
+    from mock import Mock
 
 
 def assert_commit_serialization(rwrepo, commit_id, print_performance_info=False):
@@ -57,14 +61,14 @@ def assert_commit_serialization(rwrepo, commit_id, print_performance_info=False)
         stream.seek(0)
 
         istream = rwrepo.odb.store(IStream(Commit.type, streamlen, stream))
-        assert istream.hexsha == cm.hexsha.encode('ascii')
+        assert_equal(istream.hexsha, cm.hexsha.encode('ascii'))
 
         nc = Commit(rwrepo, Commit.NULL_BIN_SHA, cm.tree,
                     cm.author, cm.authored_date, cm.author_tz_offset,
                     cm.committer, cm.committed_date, cm.committer_tz_offset,
                     cm.message, cm.parents, cm.encoding)
 
-        assert nc.parents == cm.parents
+        assert_equal(nc.parents, cm.parents)
         stream = BytesIO()
         nc._serialize(stream)
         ns += 1
@@ -78,7 +82,7 @@ def assert_commit_serialization(rwrepo, commit_id, print_performance_info=False)
         nc.binsha = rwrepo.odb.store(istream).binsha
 
         # if it worked, we have exactly the same contents !
-        assert nc.hexsha == cm.hexsha
+        assert_equal(nc.hexsha, cm.hexsha)
     # END check commits
     elapsed = time.time() - st
 
@@ -99,10 +103,10 @@ class TestCommit(TestBase):
 
         assert_equal("Sebastian Thiel", commit.author.name)
         assert_equal("byronimo@gmail.com", commit.author.email)
-        assert commit.author == commit.committer
+        self.assertEqual(commit.author, commit.committer)
         assert isinstance(commit.authored_date, int) and isinstance(commit.committed_date, int)
         assert isinstance(commit.author_tz_offset, int) and isinstance(commit.committer_tz_offset, int)
-        assert commit.message == "Added missing information to docstrings of commit and stats module\n"
+        self.assertEqual(commit.message, "Added missing information to docstrings of commit and stats module\n")
 
     def test_stats(self):
         commit = self.rorepo.commit('33ebe7acec14b25c5f84f35a664803fcab2f7781')
@@ -125,20 +129,20 @@ class TestCommit(TestBase):
 
         # assure data is parsed properly
         michael = Actor._from_string("Michael Trier <mtrier@gmail.com>")
-        assert commit.author == michael
-        assert commit.committer == michael
-        assert commit.authored_date == 1210193388
-        assert commit.committed_date == 1210193388
-        assert commit.author_tz_offset == 14400, commit.author_tz_offset
-        assert commit.committer_tz_offset == 14400, commit.committer_tz_offset
-        assert commit.message == "initial project\n"
+        self.assertEqual(commit.author, michael)
+        self.assertEqual(commit.committer, michael)
+        self.assertEqual(commit.authored_date, 1210193388)
+        self.assertEqual(commit.committed_date, 1210193388)
+        self.assertEqual(commit.author_tz_offset, 14400, commit.author_tz_offset)
+        self.assertEqual(commit.committer_tz_offset, 14400, commit.committer_tz_offset)
+        self.assertEqual(commit.message, "initial project\n")
 
     def test_unicode_actor(self):
         # assure we can parse unicode actors correctly
         name = u"Üäöß ÄußÉ"
-        assert len(name) == 9
+        self.assertEqual(len(name), 9)
         special = Actor._from_string(u"%s <something@this.com>" % name)
-        assert special.name == name
+        self.assertEqual(special.name, name)
         assert isinstance(special.name, text_type)
 
     def test_traversal(self):
@@ -152,44 +156,44 @@ class TestCommit(TestBase):
         # basic branch first, depth first
         dfirst = start.traverse(branch_first=False)
         bfirst = start.traverse(branch_first=True)
-        assert next(dfirst) == p0
-        assert next(dfirst) == p00
+        self.assertEqual(next(dfirst), p0)
+        self.assertEqual(next(dfirst), p00)
 
-        assert next(bfirst) == p0
-        assert next(bfirst) == p1
-        assert next(bfirst) == p00
-        assert next(bfirst) == p10
+        self.assertEqual(next(bfirst), p0)
+        self.assertEqual(next(bfirst), p1)
+        self.assertEqual(next(bfirst), p00)
+        self.assertEqual(next(bfirst), p10)
 
         # at some point, both iterations should stop
-        assert list(bfirst)[-1] == first
+        self.assertEqual(list(bfirst)[-1], first)
         stoptraverse = self.rorepo.commit("254d04aa3180eb8b8daf7b7ff25f010cd69b4e7d").traverse(as_edge=True)
         l = list(stoptraverse)
-        assert len(l[0]) == 2
+        self.assertEqual(len(l[0]), 2)
 
         # ignore self
-        assert next(start.traverse(ignore_self=False)) == start
+        self.assertEqual(next(start.traverse(ignore_self=False)), start)
 
         # depth
-        assert len(list(start.traverse(ignore_self=False, depth=0))) == 1
+        self.assertEqual(len(list(start.traverse(ignore_self=False, depth=0))), 1)
 
         # prune
-        assert next(start.traverse(branch_first=1, prune=lambda i, d: i == p0)) == p1
+        self.assertEqual(next(start.traverse(branch_first=1, prune=lambda i, d: i == p0)), p1)
 
         # predicate
-        assert next(start.traverse(branch_first=1, predicate=lambda i, d: i == p1)) == p1
+        self.assertEqual(next(start.traverse(branch_first=1, predicate=lambda i, d: i == p1)), p1)
 
         # traversal should stop when the beginning is reached
         self.failUnlessRaises(StopIteration, next, first.traverse())
 
         # parents of the first commit should be empty ( as the only parent has a null
         # sha )
-        assert len(first.parents) == 0
+        self.assertEqual(len(first.parents), 0)
 
     def test_iteration(self):
         # we can iterate commits
         all_commits = Commit.list_items(self.rorepo, self.rorepo.head)
         assert all_commits
-        assert all_commits == list(self.rorepo.iter_commits())
+        self.assertEqual(all_commits, list(self.rorepo.iter_commits()))
 
         # this includes merge commits
         mcomit = self.rorepo.commit('d884adc80c80300b4cc05321494713904ef1df2d')
@@ -236,7 +240,7 @@ class TestCommit(TestBase):
         list(rw_repo.iter_commits(rw_repo.head.ref))  # should fail unless bug is fixed
 
     def test_count(self):
-        assert self.rorepo.tag('refs/tags/0.1.5').commit.count() == 143
+        self.assertEqual(self.rorepo.tag('refs/tags/0.1.5').commit.count(), 143)
 
     def test_list(self):
         # This doesn't work anymore, as we will either attempt getattr with bytes, or compare 20 byte string
@@ -266,7 +270,7 @@ class TestCommit(TestBase):
             piter = c.iter_parents(skip=skip)
             first_parent = next(piter)
             assert first_parent != c
-            assert first_parent == c.parents[0]
+            self.assertEqual(first_parent, c.parents[0])
         # END for each
 
     def test_name_rev(self):
@@ -279,7 +283,7 @@ class TestCommit(TestBase):
         assert_commit_serialization(rwrepo, '0.1.6')
 
     def test_serialization_unicode_support(self):
-        assert Commit.default_encoding.lower() == 'utf-8'
+        self.assertEqual(Commit.default_encoding.lower(), 'utf-8')
 
         # create a commit with unicode in the message, and the author's name
         # Verify its serialization and deserialization
@@ -288,10 +292,10 @@ class TestCommit(TestBase):
         assert isinstance(cmt.author.name, text_type)  # same here
 
         cmt.message = u"üäêèß"
-        assert len(cmt.message) == 5
+        self.assertEqual(len(cmt.message), 5)
 
         cmt.author.name = u"äüß"
-        assert len(cmt.author.name) == 3
+        self.assertEqual(len(cmt.author.name), 3)
 
         cstream = BytesIO()
         cmt._serialize(cstream)
@@ -301,22 +305,24 @@ class TestCommit(TestBase):
         ncmt = Commit(self.rorepo, cmt.binsha)
         ncmt._deserialize(cstream)
 
-        assert cmt.author.name == ncmt.author.name
-        assert cmt.message == ncmt.message
+        self.assertEqual(cmt.author.name, ncmt.author.name)
+        self.assertEqual(cmt.message, ncmt.message)
         # actually, it can't be printed in a shell as repr wants to have ascii only
         # it appears
         cmt.author.__repr__()
 
     def test_invalid_commit(self):
         cmt = self.rorepo.commit()
-        cmt._deserialize(open(fixture_path('commit_invalid_data'), 'rb'))
+        with open(fixture_path('commit_invalid_data'), 'rb') as fd:
+            cmt._deserialize(fd)
 
-        assert cmt.author.name == u'E.Azer Ko�o�o�oculu', cmt.author.name
-        assert cmt.author.email == 'azer@kodfabrik.com', cmt.author.email
+        self.assertEqual(cmt.author.name, u'E.Azer Ko�o�o�oculu', cmt.author.name)
+        self.assertEqual(cmt.author.email, 'azer@kodfabrik.com', cmt.author.email)
 
     def test_gpgsig(self):
         cmt = self.rorepo.commit()
-        cmt._deserialize(open(fixture_path('commit_with_gpgsig'), 'rb'))
+        with open(fixture_path('commit_with_gpgsig'), 'rb') as fd:
+            cmt._deserialize(fd)
 
         fixture_sig = """-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
@@ -335,7 +341,7 @@ BX/otlTa8pNE3fWYBxURvfHnMY4i3HQT7Bc1QjImAhMnyo2vJk4ORBJIZ1FTNIhJ
 JzJMZDRLQLFvnzqZuCjE
 =przd
 -----END PGP SIGNATURE-----"""
-        assert cmt.gpgsig == fixture_sig
+        self.assertEqual(cmt.gpgsig, fixture_sig)
 
         cmt.gpgsig = "<test\ndummy\nsig>"
         assert cmt.gpgsig != fixture_sig
@@ -343,39 +349,39 @@ JzJMZDRLQLFvnzqZuCjE
         cstream = BytesIO()
         cmt._serialize(cstream)
         assert re.search(r"^gpgsig <test\n dummy\n sig>$", cstream.getvalue().decode('ascii'), re.MULTILINE)
-        
+
         self.assert_gpgsig_deserialization(cstream)
-        
+
         cstream.seek(0)
         cmt.gpgsig = None
         cmt._deserialize(cstream)
-        assert cmt.gpgsig == "<test\ndummy\nsig>"
+        self.assertEqual(cmt.gpgsig, "<test\ndummy\nsig>")
 
         cmt.gpgsig = None
         cstream = BytesIO()
         cmt._serialize(cstream)
         assert not re.search(r"^gpgsig ", cstream.getvalue().decode('ascii'), re.MULTILINE)
-        
+
     def assert_gpgsig_deserialization(self, cstream):
         assert 'gpgsig' in 'precondition: need gpgsig'
-        
+
         class RepoMock:
             def __init__(self, bytestr):
                 self.bytestr = bytestr
-                
+
             @property
             def odb(self):
                 class ODBMock:
                     def __init__(self, bytestr):
                         self.bytestr = bytestr
-                        
+
                     def stream(self, *args):
                         stream = Mock(spec_set=['read'], return_value=self.bytestr)
                         stream.read.return_value = self.bytestr
                         return ('binsha', 'typename', 'size', stream)
-                        
+
                 return ODBMock(self.bytestr)
-                    
+
         repo_mock = RepoMock(cstream.getvalue())
         for field in Commit.__slots__:
             c = Commit(repo_mock, b'x' * 20)
@@ -383,9 +389,13 @@ JzJMZDRLQLFvnzqZuCjE
 
     def test_datetimes(self):
         commit = self.rorepo.commit('4251bd5')
-        assert commit.authored_date == 1255018625
-        assert commit.committed_date == 1255026171
-        assert commit.authored_datetime == datetime(2009, 10, 8, 18, 17, 5, tzinfo=tzoffset(-7200)), commit.authored_datetime  # noqa
-        assert commit.authored_datetime == datetime(2009, 10, 8, 16, 17, 5, tzinfo=utc), commit.authored_datetime
-        assert commit.committed_datetime == datetime(2009, 10, 8, 20, 22, 51, tzinfo=tzoffset(-7200))
-        assert commit.committed_datetime == datetime(2009, 10, 8, 18, 22, 51, tzinfo=utc), commit.committed_datetime
+        self.assertEqual(commit.authored_date, 1255018625)
+        self.assertEqual(commit.committed_date, 1255026171)
+        self.assertEqual(commit.authored_datetime,
+                         datetime(2009, 10, 8, 18, 17, 5, tzinfo=tzoffset(-7200)), commit.authored_datetime)  # noqa
+        self.assertEqual(commit.authored_datetime,
+                         datetime(2009, 10, 8, 16, 17, 5, tzinfo=utc), commit.authored_datetime)
+        self.assertEqual(commit.committed_datetime,
+                         datetime(2009, 10, 8, 20, 22, 51, tzinfo=tzoffset(-7200)))
+        self.assertEqual(commit.committed_datetime,
+                         datetime(2009, 10, 8, 18, 22, 51, tzinfo=utc), commit.committed_datetime)
diff --git a/git/test/test_config.py b/git/test/test_config.py
index c0889c1a..154aaa24 100644
--- a/git/test/test_config.py
+++ b/git/test/test_config.py
@@ -4,28 +4,45 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
-from git.test.lib import (
-    TestCase,
-    fixture_path,
-    assert_equal,
-)
-from gitdb.test.lib import with_rw_directory
+import glob
+import io
+import os
+
 from git import (
     GitConfigParser
 )
-from git.compat import (
-    string_types,
-)
-import io
-import os
+from git.compat import string_types
 from git.config import cp
+from git.test.lib import (
+    TestCase,
+    fixture_path,
+)
+from git.test.lib import with_rw_directory
+
+import os.path as osp
+from git.util import rmfile
+
+
+_tc_lock_fpaths = osp.join(osp.dirname(__file__), 'fixtures/*.lock')
+
+
+def _rm_lock_files():
+    for lfp in glob.glob(_tc_lock_fpaths):
+        rmfile(lfp)
 
 
 class TestBase(TestCase):
+    def setUp(self):
+        _rm_lock_files()
+
+    def tearDown(self):
+        for lfp in glob.glob(_tc_lock_fpaths):
+            if osp.isfile(lfp):
+                raise AssertionError('Previous TC left hanging git-lock file: %s', lfp)
 
     def _to_memcache(self, file_path):
-        fp = open(file_path, "rb")
-        sio = io.BytesIO(fp.read())
+        with open(file_path, "rb") as fp:
+            sio = io.BytesIO(fp.read())
         sio.name = file_path
         return sio
 
@@ -33,51 +50,49 @@ class TestBase(TestCase):
         # writer must create the exact same file as the one read before
         for filename in ("git_config", "git_config_global"):
             file_obj = self._to_memcache(fixture_path(filename))
-            w_config = GitConfigParser(file_obj, read_only=False)
-            w_config.read()                 # enforce reading
-            assert w_config._sections
-            w_config.write()                # enforce writing
-
-            # we stripped lines when reading, so the results differ
-            assert file_obj.getvalue()
-            self.assertEqual(file_obj.getvalue(), self._to_memcache(fixture_path(filename)).getvalue())
-
-            # creating an additional config writer must fail due to exclusive access
-            self.failUnlessRaises(IOError, GitConfigParser, file_obj, read_only=False)
-
-            # should still have a lock and be able to make changes
-            assert w_config._lock._has_lock()
-
-            # changes should be written right away
-            sname = "my_section"
-            oname = "mykey"
-            val = "myvalue"
-            w_config.add_section(sname)
-            assert w_config.has_section(sname)
-            w_config.set(sname, oname, val)
-            assert w_config.has_option(sname, oname)
-            assert w_config.get(sname, oname) == val
-
-            sname_new = "new_section"
-            oname_new = "new_key"
-            ival = 10
-            w_config.set_value(sname_new, oname_new, ival)
-            assert w_config.get_value(sname_new, oname_new) == ival
-
-            file_obj.seek(0)
-            r_config = GitConfigParser(file_obj, read_only=True)
-            assert r_config.has_section(sname)
-            assert r_config.has_option(sname, oname)
-            assert r_config.get(sname, oname) == val
-            w_config.release()
+            with GitConfigParser(file_obj, read_only=False) as w_config:
+                w_config.read()                 # enforce reading
+                assert w_config._sections
+                w_config.write()                # enforce writing
+
+                # we stripped lines when reading, so the results differ
+                assert file_obj.getvalue()
+                self.assertEqual(file_obj.getvalue(), self._to_memcache(fixture_path(filename)).getvalue())
+
+                # creating an additional config writer must fail due to exclusive access
+                self.failUnlessRaises(IOError, GitConfigParser, file_obj, read_only=False)
+
+                # should still have a lock and be able to make changes
+                assert w_config._lock._has_lock()
+
+                # changes should be written right away
+                sname = "my_section"
+                oname = "mykey"
+                val = "myvalue"
+                w_config.add_section(sname)
+                assert w_config.has_section(sname)
+                w_config.set(sname, oname, val)
+                assert w_config.has_option(sname, oname)
+                assert w_config.get(sname, oname) == val
+
+                sname_new = "new_section"
+                oname_new = "new_key"
+                ival = 10
+                w_config.set_value(sname_new, oname_new, ival)
+                assert w_config.get_value(sname_new, oname_new) == ival
+
+                file_obj.seek(0)
+                r_config = GitConfigParser(file_obj, read_only=True)
+                assert r_config.has_section(sname)
+                assert r_config.has_option(sname, oname)
+                assert r_config.get(sname, oname) == val
         # END for each filename
 
     @with_rw_directory
     def test_lock_reentry(self, rw_dir):
         fpl = os.path.join(rw_dir, 'l')
-        gcp = GitConfigParser(fpl, read_only=False)
-        with gcp as cw:
-            cw.set_value('include', 'some_value', 'a')
+        with GitConfigParser(fpl, read_only=False) as gcp:
+            gcp.set_value('include', 'some_value', 'a')
         # entering again locks the file again...
         with gcp as cw:
             cw.set_value('include', 'some_other_value', 'b')
@@ -91,21 +106,21 @@ class TestBase(TestCase):
 
     def test_multi_line_config(self):
         file_obj = self._to_memcache(fixture_path("git_config_with_comments"))
-        config = GitConfigParser(file_obj, read_only=False)
-        ev = "ruby -e '\n"
-        ev += "		system %(git), %(merge-file), %(--marker-size=%L), %(%A), %(%O), %(%B)\n"
-        ev += "		b = File.read(%(%A))\n"
-        ev += "		b.sub!(/^<+ .*\\nActiveRecord::Schema\\.define.:version => (\\d+). do\\n=+\\nActiveRecord::Schema\\."
-        ev += "define.:version => (\\d+). do\\n>+ .*/) do\n"
-        ev += "		  %(ActiveRecord::Schema.define(:version => #{[$1, $2].max}) do)\n"
-        ev += "		end\n"
-        ev += "		File.open(%(%A), %(w)) {|f| f.write(b)}\n"
-        ev += "		exit 1 if b.include?(%(<)*%L)'"
-        assert_equal(config.get('merge "railsschema"', 'driver'), ev)
-        assert_equal(config.get('alias', 'lg'),
-                     "log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr)%Creset'"
-                     " --abbrev-commit --date=relative")
-        assert len(config.sections()) == 23
+        with GitConfigParser(file_obj, read_only=False) as config:
+            ev = "ruby -e '\n"
+            ev += "		system %(git), %(merge-file), %(--marker-size=%L), %(%A), %(%O), %(%B)\n"
+            ev += "		b = File.read(%(%A))\n"
+            ev += "		b.sub!(/^<+ .*\\nActiveRecord::Schema\\.define.:version => (\\d+). do\\n=+\\nActiveRecord::Schema\\."  # noqa E501
+            ev += "define.:version => (\\d+). do\\n>+ .*/) do\n"
+            ev += "		  %(ActiveRecord::Schema.define(:version => #{[$1, $2].max}) do)\n"
+            ev += "		end\n"
+            ev += "		File.open(%(%A), %(w)) {|f| f.write(b)}\n"
+            ev += "		exit 1 if b.include?(%(<)*%L)'"
+            self.assertEqual(config.get('merge "railsschema"', 'driver'), ev)
+            self.assertEqual(config.get('alias', 'lg'),
+                             "log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr)%Creset'"
+                             " --abbrev-commit --date=relative")
+            self.assertEqual(len(config.sections()), 23)
 
     def test_base(self):
         path_repo = fixture_path("git_config")
@@ -202,22 +217,19 @@ class TestBase(TestCase):
 
     def test_rename(self):
         file_obj = self._to_memcache(fixture_path('git_config'))
-        cw = GitConfigParser(file_obj, read_only=False, merge_includes=False)
-
-        self.failUnlessRaises(ValueError, cw.rename_section, "doesntexist", "foo")
-        self.failUnlessRaises(ValueError, cw.rename_section, "core", "include")
+        with GitConfigParser(file_obj, read_only=False, merge_includes=False) as cw:
+            self.failUnlessRaises(ValueError, cw.rename_section, "doesntexist", "foo")
+            self.failUnlessRaises(ValueError, cw.rename_section, "core", "include")
 
-        nn = "bee"
-        assert cw.rename_section('core', nn) is cw
-        assert not cw.has_section('core')
-        assert len(cw.items(nn)) == 4
-        cw.release()
+            nn = "bee"
+            assert cw.rename_section('core', nn) is cw
+            assert not cw.has_section('core')
+            assert len(cw.items(nn)) == 4
 
     def test_complex_aliases(self):
         file_obj = self._to_memcache(fixture_path('.gitconfig'))
-        w_config = GitConfigParser(file_obj, read_only=False)
-        self.assertEqual(w_config.get('alias', 'rbi'), '"!g() { git rebase -i origin/${1:-master} ; } ; g"')
-        w_config.release()
+        with GitConfigParser(file_obj, read_only=False) as w_config:
+            self.assertEqual(w_config.get('alias', 'rbi'), '"!g() { git rebase -i origin/${1:-master} ; } ; g"')
         self.assertEqual(file_obj.getvalue(), self._to_memcache(fixture_path('.gitconfig')).getvalue())
 
     def test_empty_config_value(self):
diff --git a/git/test/test_diff.py b/git/test/test_diff.py
index 9fdb26a2..d34d84e3 100644
--- a/git/test/test_diff.py
+++ b/git/test/test_diff.py
@@ -15,7 +15,7 @@ from git.test.lib import (
 
 )
 
-from gitdb.test.lib import with_rw_directory
+from git.test.lib import with_rw_directory
 
 from git import (
     Repo,
@@ -24,10 +24,16 @@ from git import (
     DiffIndex,
     NULL_TREE,
 )
+import ddt
 
 
+@ddt.ddt
 class TestDiff(TestBase):
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     def _assert_diff_format(self, diffs):
         # verify that the format of the diff is sane
         for diff in diffs:
@@ -66,13 +72,14 @@ class TestDiff(TestBase):
         self.failUnlessRaises(GitCommandError, r.git.cherry_pick, 'master')
 
         # Now do the actual testing - this should just work
-        assert len(r.index.diff(None)) == 2
+        self.assertEqual(len(r.index.diff(None)), 2)
 
-        assert len(r.index.diff(None, create_patch=True)) == 0, "This should work, but doesn't right now ... it's OK"
+        self.assertEqual(len(r.index.diff(None, create_patch=True)), 0,
+                         "This should work, but doesn't right now ... it's OK")
 
     def test_list_from_string_new_mode(self):
         output = StringProcessAdapter(fixture('diff_new_mode'))
-        diffs = Diff._index_from_patch_format(self.rorepo, output.stdout)
+        diffs = Diff._index_from_patch_format(self.rorepo, output)
         self._assert_diff_format(diffs)
 
         assert_equal(1, len(diffs))
@@ -80,7 +87,7 @@ class TestDiff(TestBase):
 
     def test_diff_with_rename(self):
         output = StringProcessAdapter(fixture('diff_rename'))
-        diffs = Diff._index_from_patch_format(self.rorepo, output.stdout)
+        diffs = Diff._index_from_patch_format(self.rorepo, output)
         self._assert_diff_format(diffs)
 
         assert_equal(1, len(diffs))
@@ -95,42 +102,46 @@ class TestDiff(TestBase):
         assert isinstance(str(diff), str)
 
         output = StringProcessAdapter(fixture('diff_rename_raw'))
-        diffs = Diff._index_from_raw_format(self.rorepo, output.stdout)
-        assert len(diffs) == 1
+        diffs = Diff._index_from_raw_format(self.rorepo, output)
+        self.assertEqual(len(diffs), 1)
         diff = diffs[0]
-        assert diff.renamed_file
-        assert diff.renamed
-        assert diff.rename_from == 'this'
-        assert diff.rename_to == 'that'
-        assert len(list(diffs.iter_change_type('R'))) == 1
+        self.assertIsNotNone(diff.renamed_file)
+        self.assertIsNotNone(diff.renamed)
+        self.assertEqual(diff.rename_from, 'this')
+        self.assertEqual(diff.rename_to, 'that')
+        self.assertEqual(len(list(diffs.iter_change_type('R'))), 1)
 
     def test_diff_of_modified_files_not_added_to_the_index(self):
         output = StringProcessAdapter(fixture('diff_abbrev-40_full-index_M_raw_no-color'))
-        diffs = Diff._index_from_raw_format(self.rorepo, output.stdout)
-        
-        assert len(diffs) == 1, 'one modification'
-        assert len(list(diffs.iter_change_type('M'))) == 1, 'one modification'
-        assert diffs[0].change_type == 'M'
-        assert diffs[0].b_blob is None
-        
-    def test_binary_diff(self):
-        for method, file_name in ((Diff._index_from_patch_format, 'diff_patch_binary'),
-                                  (Diff._index_from_raw_format, 'diff_raw_binary')):
-            res = method(None, StringProcessAdapter(fixture(file_name)).stdout)
-            assert len(res) == 1
-            assert len(list(res.iter_change_type('M'))) == 1
-            if res[0].diff:
-                assert res[0].diff == b"Binary files a/rps and b/rps differ\n", "in patch mode, we get a diff text"
-                assert str(res[0]), "This call should just work"
-        # end for each method to test
+        diffs = Diff._index_from_raw_format(self.rorepo, output)
+
+        self.assertEqual(len(diffs), 1, 'one modification')
+        self.assertEqual(len(list(diffs.iter_change_type('M'))), 1, 'one modification')
+        self.assertEqual(diffs[0].change_type, 'M')
+        self.assertIsNone(diffs[0].b_blob,)
+
+    @ddt.data(
+        (Diff._index_from_patch_format, 'diff_patch_binary'),
+        (Diff._index_from_raw_format, 'diff_raw_binary')
+    )
+    def test_binary_diff(self, case):
+        method, file_name = case
+        res = method(None, StringProcessAdapter(fixture(file_name)))
+        self.assertEqual(len(res), 1)
+        self.assertEqual(len(list(res.iter_change_type('M'))), 1)
+        if res[0].diff:
+            self.assertEqual(res[0].diff,
+                             b"Binary files a/rps and b/rps differ\n",
+                             "in patch mode, we get a diff text")
+            self.assertIsNotNone(str(res[0]), "This call should just work")
 
     def test_diff_index(self):
         output = StringProcessAdapter(fixture('diff_index_patch'))
-        res = Diff._index_from_patch_format(None, output.stdout)
-        assert len(res) == 6
+        res = Diff._index_from_patch_format(None, output)
+        self.assertEqual(len(res), 6)
         for dr in res:
-            assert dr.diff.startswith(b'@@')
-            assert str(dr), "Diff to string conversion should be possible"
+            self.assertTrue(dr.diff.startswith(b'@@'), dr)
+            self.assertIsNotNone(str(dr), "Diff to string conversion should be possible")
         # end for each diff
 
         dr = res[3]
@@ -138,29 +149,29 @@ class TestDiff(TestBase):
 
     def test_diff_index_raw_format(self):
         output = StringProcessAdapter(fixture('diff_index_raw'))
-        res = Diff._index_from_raw_format(None, output.stdout)
-        assert res[0].deleted_file
-        assert res[0].b_path is None
+        res = Diff._index_from_raw_format(None, output)
+        self.assertIsNotNone(res[0].deleted_file)
+        self.assertIsNone(res[0].b_path,)
 
     def test_diff_initial_commit(self):
         initial_commit = self.rorepo.commit('33ebe7acec14b25c5f84f35a664803fcab2f7781')
 
         # Without creating a patch...
         diff_index = initial_commit.diff(NULL_TREE)
-        assert diff_index[0].b_path == 'CHANGES'
-        assert diff_index[0].new_file
-        assert diff_index[0].diff == ''
+        self.assertEqual(diff_index[0].b_path, 'CHANGES')
+        self.assertIsNotNone(diff_index[0].new_file)
+        self.assertEqual(diff_index[0].diff, '')
 
         # ...and with creating a patch
         diff_index = initial_commit.diff(NULL_TREE, create_patch=True)
-        assert diff_index[0].a_path is None, repr(diff_index[0].a_path)
-        assert diff_index[0].b_path == 'CHANGES', repr(diff_index[0].b_path)
-        assert diff_index[0].new_file
-        assert diff_index[0].diff == fixture('diff_initial')
+        self.assertIsNone(diff_index[0].a_path, repr(diff_index[0].a_path))
+        self.assertEqual(diff_index[0].b_path, 'CHANGES', repr(diff_index[0].b_path))
+        self.assertIsNotNone(diff_index[0].new_file)
+        self.assertEqual(diff_index[0].diff, fixture('diff_initial'))
 
     def test_diff_unsafe_paths(self):
         output = StringProcessAdapter(fixture('diff_patch_unsafe_paths'))
-        res = Diff._index_from_patch_format(None, output.stdout)
+        res = Diff._index_from_patch_format(None, output)
 
         # The "Additions"
         self.assertEqual(res[0].b_path, u'path/ starting with a space')
@@ -196,14 +207,14 @@ class TestDiff(TestBase):
 
         for fixture_name in fixtures:
             diff_proc = StringProcessAdapter(fixture(fixture_name))
-            Diff._index_from_patch_format(self.rorepo, diff_proc.stdout)
+            Diff._index_from_patch_format(self.rorepo, diff_proc)
         # END for each fixture
 
     def test_diff_with_spaces(self):
         data = StringProcessAdapter(fixture('diff_file_with_spaces'))
-        diff_index = Diff._index_from_patch_format(self.rorepo, data.stdout)
-        assert diff_index[0].a_path is None, repr(diff_index[0].a_path)
-        assert diff_index[0].b_path == u'file with spaces', repr(diff_index[0].b_path)
+        diff_index = Diff._index_from_patch_format(self.rorepo, data)
+        self.assertIsNone(diff_index[0].a_path, repr(diff_index[0].a_path))
+        self.assertEqual(diff_index[0].b_path, u'file with spaces', repr(diff_index[0].b_path))
 
     def test_diff_interface(self):
         # test a few variations of the main diff routine
@@ -232,12 +243,12 @@ class TestDiff(TestBase):
                             diff_set = set()
                             diff_set.add(diff_index[0])
                             diff_set.add(diff_index[0])
-                            assert len(diff_set) == 1
-                            assert diff_index[0] == diff_index[0]
-                            assert not (diff_index[0] != diff_index[0])
+                            self.assertEqual(len(diff_set), 1)
+                            self.assertEqual(diff_index[0], diff_index[0])
+                            self.assertFalse(diff_index[0] != diff_index[0])
 
                             for dr in diff_index:
-                                assert str(dr), "Diff to string conversion should be possible"
+                                self.assertIsNotNone(str(dr), "Diff to string conversion should be possible")
                         # END diff index checking
                     # END for each patch option
                 # END for each path option
@@ -248,11 +259,11 @@ class TestDiff(TestBase):
         # can iterate in the diff index - if not this indicates its not working correctly
         # or our test does not span the whole range of possibilities
         for key, value in assertion_map.items():
-            assert value, "Did not find diff for %s" % key
+            self.assertIsNotNone(value, "Did not find diff for %s" % key)
         # END for each iteration type
 
         # test path not existing in the index - should be ignored
         c = self.rorepo.head.commit
         cp = c.parents[0]
         diff_index = c.diff(cp, ["does/not/exist"])
-        assert len(diff_index) == 0
+        self.assertEqual(len(diff_index), 0)
diff --git a/git/test/test_docs.py b/git/test/test_docs.py
index b297363d..8a2dff0f 100644
--- a/git/test/test_docs.py
+++ b/git/test/test_docs.py
@@ -7,10 +7,15 @@
 import os
 
 from git.test.lib import TestBase
-from gitdb.test.lib import with_rw_directory
+from git.test.lib.helper import with_rw_directory
 
 
 class Tutorials(TestBase):
+
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     @with_rw_directory
     def test_init_repo_object(self, rw_dir):
         # [1-test_init_repo_object]
@@ -48,33 +53,34 @@ class Tutorials(TestBase):
         # ![5-test_init_repo_object]
 
         # [6-test_init_repo_object]
-        repo.archive(open(join(rw_dir, 'repo.tar'), 'wb'))
+        with open(join(rw_dir, 'repo.tar'), 'wb') as fp:
+            repo.archive(fp)
         # ![6-test_init_repo_object]
 
         # repository paths
         # [7-test_init_repo_object]
-        assert os.path.isdir(cloned_repo.working_tree_dir)                    # directory with your work files
-        assert cloned_repo.git_dir.startswith(cloned_repo.working_tree_dir)   # directory containing the git repository
-        assert bare_repo.working_tree_dir is None                             # bare repositories have no working tree
+        assert os.path.isdir(cloned_repo.working_tree_dir)                   # directory with your work files
+        assert cloned_repo.git_dir.startswith(cloned_repo.working_tree_dir)  # directory containing the git repository
+        assert bare_repo.working_tree_dir is None                            # bare repositories have no working tree
         # ![7-test_init_repo_object]
 
         # heads, tags and references
         # heads are branches in git-speak
         # [8-test_init_repo_object]
-        assert repo.head.ref == repo.heads.master                   # head is a symbolic reference pointing to master
-        assert repo.tags['0.3.5'] == repo.tag('refs/tags/0.3.5')    # you can access tags in various ways too
-        assert repo.refs.master == repo.heads['master']             # .refs provides access to all refs, i.e. heads ...
-        
+        self.assertEqual(repo.head.ref, repo.heads.master)                  # head is a sym-ref pointing to master
+        self.assertEqual(repo.tags['0.3.5'], repo.tag('refs/tags/0.3.5'))   # you can access tags in various ways too
+        self.assertEqual(repo.refs.master, repo.heads['master'])            # .refs provides all refs, ie heads ...
+
         if 'TRAVIS' not in os.environ:
-            assert repo.refs['origin/master'] == repo.remotes.origin.refs.master  # ... remotes ...
-        assert repo.refs['0.3.5'] == repo.tags['0.3.5']             # ... and tags
+            self.assertEqual(repo.refs['origin/master'], repo.remotes.origin.refs.master)  # ... remotes ...
+        self.assertEqual(repo.refs['0.3.5'], repo.tags['0.3.5'])             # ... and tags
         # ![8-test_init_repo_object]
 
         # create a new head/branch
         # [9-test_init_repo_object]
         new_branch = cloned_repo.create_head('feature')               # create a new branch ...
         assert cloned_repo.active_branch != new_branch                # which wasn't checked out yet ...
-        assert new_branch.commit == cloned_repo.active_branch.commit  # and which points to the checked-out commit
+        self.assertEqual(new_branch.commit, cloned_repo.active_branch.commit)  # pointing to the checked-out commit
         # It's easy to let a branch point to the previous commit, without affecting anything else
         # Each reference provides access to the git object it points to, usually commits
         assert new_branch.set_commit('HEAD~1').commit == cloned_repo.active_branch.commit.parents[0]
@@ -84,7 +90,7 @@ class Tutorials(TestBase):
         # [10-test_init_repo_object]
         past = cloned_repo.create_tag('past', ref=new_branch,
                                       message="This is a tag-object pointing to %s" % new_branch.name)
-        assert past.commit == new_branch.commit        # the tag points to the specified commit
+        self.assertEqual(past.commit, new_branch.commit)        # the tag points to the specified commit
         assert past.tag.message.startswith("This is")  # and its object carries the message provided
 
         now = cloned_repo.create_tag('now')            # This is a tag-reference. It may not carry meta-data
@@ -105,7 +111,7 @@ class Tutorials(TestBase):
             file_count += item.type == 'blob'
             tree_count += item.type == 'tree'
         assert file_count and tree_count                        # we have accumulated all directories and files
-        assert len(tree.blobs) + len(tree.trees) == len(tree)   # a tree is iterable itself to traverse its children
+        self.assertEqual(len(tree.blobs) + len(tree.trees), len(tree))   # a tree is iterable on its children
         # ![11-test_init_repo_object]
 
         # remotes allow handling push, pull and fetch operations
@@ -117,8 +123,8 @@ class Tutorials(TestBase):
                 print(op_code, cur_count, max_count, cur_count / (max_count or 100.0), message or "NO MESSAGE")
         # end
 
-        assert len(cloned_repo.remotes) == 1                    # we have been cloned, so there should be one remote
-        assert len(bare_repo.remotes) == 0                      # this one was just initialized
+        self.assertEqual(len(cloned_repo.remotes), 1)                    # we have been cloned, so should be one remote
+        self.assertEqual(len(bare_repo.remotes), 0)                      # this one was just initialized
         origin = bare_repo.create_remote('origin', url=cloned_repo.working_tree_dir)
         assert origin.exists()
         for fetch_info in origin.fetch(progress=MyProgressPrinter()):
@@ -133,8 +139,8 @@ class Tutorials(TestBase):
 
         # index
         # [13-test_init_repo_object]
-        assert new_branch.checkout() == cloned_repo.active_branch     # checking out a branch adjusts the working tree
-        assert new_branch.commit == past.commit                       # Now the past is checked out
+        self.assertEqual(new_branch.checkout(), cloned_repo.active_branch)     # checking out branch adjusts the wtree
+        self.assertEqual(new_branch.commit, past.commit)                       # Now the past is checked out
 
         new_file_path = os.path.join(cloned_repo.working_tree_dir, 'my-new-file')
         open(new_file_path, 'wb').close()                             # create new file in working tree
@@ -205,7 +211,7 @@ class Tutorials(TestBase):
         master = head.reference     # retrieve the reference the head points to
         master.commit               # from here you use it as any other reference
         # ![3-test_references_and_objects]
-
+#
         # [4-test_references_and_objects]
         log = master.log()
         log[0]                      # first (i.e. oldest) reflog entry
@@ -239,17 +245,17 @@ class Tutorials(TestBase):
         # ![8-test_references_and_objects]
 
         # [9-test_references_and_objects]
-        assert hct.type == 'tree'           # preset string type, being a class attribute
+        self.assertEqual(hct.type, 'tree')           # preset string type, being a class attribute
         assert hct.size > 0                 # size in bytes
         assert len(hct.hexsha) == 40
         assert len(hct.binsha) == 20
         # ![9-test_references_and_objects]
 
         # [10-test_references_and_objects]
-        assert hct.path == ''                  # root tree has no path
+        self.assertEqual(hct.path, '')                  # root tree has no path
         assert hct.trees[0].path != ''         # the first contained item has one though
-        assert hct.mode == 0o40000              # trees have the mode of a linux directory
-        assert hct.blobs[0].mode == 0o100644   # blobs have a specific mode though comparable to a standard linux fs
+        self.assertEqual(hct.mode, 0o40000)              # trees have the mode of a linux directory
+        self.assertEqual(hct.blobs[0].mode, 0o100644)   # blobs have specific mode, comparable to a standard linux fs
         # ![10-test_references_and_objects]
 
         # [11-test_references_and_objects]
@@ -306,14 +312,14 @@ class Tutorials(TestBase):
         # ![18-test_references_and_objects]
 
         # [19-test_references_and_objects]
-        assert tree['smmap'] == tree / 'smmap'          # access by index and by sub-path
+        self.assertEqual(tree['smmap'], tree / 'smmap')          # access by index and by sub-path
         for entry in tree:                                         # intuitive iteration of tree members
             print(entry)
         blob = tree.trees[0].blobs[0]                              # let's get a blob in a sub-tree
         assert blob.name
         assert len(blob.path) < len(blob.abspath)
-        assert tree.trees[0].name + '/' + blob.name == blob.path   # this is how the relative blob path is generated
-        assert tree[blob.path] == blob                             # you can use paths like 'dir/file' in tree[...]
+        self.assertEqual(tree.trees[0].name + '/' + blob.name, blob.path)   # this is how relative blob path generated
+        self.assertEqual(tree[blob.path], blob)                             # you can use paths like 'dir/file' in tree
         # ![19-test_references_and_objects]
 
         # [20-test_references_and_objects]
@@ -326,7 +332,7 @@ class Tutorials(TestBase):
         assert repo.tree() == repo.head.commit.tree
         past = repo.commit('HEAD~5')
         assert repo.tree(past) == repo.tree(past.hexsha)
-        assert repo.tree('v0.8.1').type == 'tree'               # yes, you can provide any refspec - works everywhere
+        self.assertEqual(repo.tree('v0.8.1').type, 'tree')        # yes, you can provide any refspec - works everywhere
         # ![21-test_references_and_objects]
 
         # [22-test_references_and_objects]
@@ -346,7 +352,7 @@ class Tutorials(TestBase):
         index.remove(['LICENSE'])                                              # remove an existing one
         assert os.path.isfile(os.path.join(repo.working_tree_dir, 'LICENSE'))  # working tree is untouched
 
-        assert index.commit("my commit message").type == 'commit'              # commit changed index
+        self.assertEqual(index.commit("my commit message").type, 'commit')              # commit changed index
         repo.active_branch.commit = repo.commit('HEAD~1')                      # forget last commit
 
         from git import Actor
@@ -373,7 +379,7 @@ class Tutorials(TestBase):
         assert origin == empty_repo.remotes.origin == empty_repo.remotes['origin']
         origin.fetch()                  # assure we actually have data. fetch() returns useful information
         # Setup a local tracking branch of a remote branch
-        empty_repo.create_head('master', origin.refs.master)  # create local branch "master" from remote branch "master"
+        empty_repo.create_head('master', origin.refs.master)  # create local branch "master" from remote "master"
         empty_repo.heads.master.set_tracking_branch(origin.refs.master)  # set local "master" to track remote "master
         empty_repo.heads.master.checkout()  # checkout local "master" to working tree
         # Three above commands in one:
@@ -443,6 +449,8 @@ class Tutorials(TestBase):
         git.for_each_ref()                              # '-' becomes '_' when calling it
         # ![31-test_references_and_objects]
 
+        repo.git.clear_cache()
+
     def test_submodules(self):
         # [1-test_submodules]
         repo = self.rorepo
@@ -450,19 +458,19 @@ class Tutorials(TestBase):
 
         assert len(sms) == 1
         sm = sms[0]
-        assert sm.name == 'gitdb'                         # git-python has gitdb as single submodule ...
-        assert sm.children()[0].name == 'smmap'           # ... which has smmap as single submodule
+        self.assertEqual(sm.name, 'gitdb')                         # git-python has gitdb as single submodule ...
+        self.assertEqual(sm.children()[0].name, 'smmap')           # ... which has smmap as single submodule
 
         # The module is the repository referenced by the submodule
         assert sm.module_exists()                         # the module is available, which doesn't have to be the case.
         assert sm.module().working_tree_dir.endswith('gitdb')
         # the submodule's absolute path is the module's path
         assert sm.abspath == sm.module().working_tree_dir
-        assert len(sm.hexsha) == 40                       # Its sha defines the commit to checkout
+        self.assertEqual(len(sm.hexsha), 40)                       # Its sha defines the commit to checkout
         assert sm.exists()                                # yes, this submodule is valid and exists
         # read its configuration conveniently
         assert sm.config_reader().get_value('path') == sm.path
-        assert len(sm.children()) == 1                    # query the submodule hierarchy
+        self.assertEqual(len(sm.children()), 1)                    # query the submodule hierarchy
         # ![1-test_submodules]
 
     @with_rw_directory
diff --git a/git/test/test_exc.py b/git/test/test_exc.py
new file mode 100644
index 00000000..7e6b023e
--- /dev/null
+++ b/git/test/test_exc.py
@@ -0,0 +1,142 @@
+# -*- coding: utf-8 -*-
+# test_exc.py
+# Copyright (C) 2008, 2009, 2016 Michael Trier (mtrier@gmail.com) and contributors
+#
+# This module is part of GitPython and is released under
+# the BSD License: http://www.opensource.org/licenses/bsd-license.php
+
+
+import re
+
+import ddt
+from git.exc import (
+    CommandError,
+    GitCommandNotFound,
+    GitCommandError,
+    HookExecutionError,
+)
+from git.test.lib import TestBase
+
+import itertools as itt
+
+
+_cmd_argvs = (
+    ('cmd', ),
+    ('θνιψοδε', ),
+    ('θνιψοδε', 'normal', 'argvs'),
+    ('cmd', 'ελληνικα', 'args'),
+    ('θνιψοδε', 'κι', 'αλλα', 'strange', 'args'),
+    ('θνιψοδε', 'κι', 'αλλα', 'non-unicode', 'args'),
+)
+_causes_n_substrings = (
+    (None,                      None),                          # noqa: E241
+    (7,                         "exit code(7)"),                           # noqa: E241
+    ('Some string',             "'Some string'"),               # noqa: E241
+    ('παλιο string',            "'παλιο string'"),              # noqa: E241
+    (Exception("An exc."),      "Exception('An exc.')"),        # noqa: E241
+    (Exception("Κακια exc."),   "Exception('Κακια exc.')"),     # noqa: E241
+    (object(),                  "<object object at "),         # noqa: E241
+)
+
+_streams_n_substrings = (None, 'steram', 'ομορφο stream', )
+
+
+@ddt.ddt
+class TExc(TestBase):
+
+    @ddt.data(*list(itt.product(_cmd_argvs, _causes_n_substrings, _streams_n_substrings)))
+    def test_CommandError_unicode(self, case):
+        argv, (cause, subs), stream = case
+        cls = CommandError
+        c = cls(argv, cause)
+        s = str(c)
+
+        self.assertIsNotNone(c._msg)
+        self.assertIn('  cmdline: ', s)
+
+        for a in argv:
+            self.assertIn(a, s)
+
+        if not cause:
+            self.assertIn("failed!", s)
+        else:
+            self.assertIn(" failed due to:", s)
+
+            if subs is not None:
+                # Substrings (must) already contain opening `'`.
+                subs = "(?<!')%s(?!')" % re.escape(subs)
+                self.assertRegexpMatches(s, subs)
+
+        if not stream:
+            c = cls(argv, cause)
+            s = str(c)
+            self.assertNotIn("  stdout:", s)
+            self.assertNotIn("  stderr:", s)
+        else:
+            c = cls(argv, cause, stream)
+            s = str(c)
+            self.assertIn("  stderr:", s)
+            self.assertIn(stream, s)
+
+            c = cls(argv, cause, None, stream)
+            s = str(c)
+            self.assertIn("  stdout:", s)
+            self.assertIn(stream, s)
+
+            c = cls(argv, cause, stream, stream + 'no2')
+            s = str(c)
+            self.assertIn("  stderr:", s)
+            self.assertIn(stream, s)
+            self.assertIn("  stdout:", s)
+            self.assertIn(stream + 'no2', s)
+
+    @ddt.data(
+        (['cmd1'], None),
+        (['cmd1'], "some cause"),
+        (['cmd1'], Exception()),
+    )
+    def test_GitCommandNotFound(self, init_args):
+        argv, cause = init_args
+        c = GitCommandNotFound(argv, cause)
+        s = str(c)
+
+        self.assertIn(argv[0], s)
+        if cause:
+            self.assertIn(' not found due to: ', s)
+            self.assertIn(str(cause), s)
+        else:
+            self.assertIn(' not found!', s)
+
+    @ddt.data(
+        (['cmd1'], None),
+        (['cmd1'], "some cause"),
+        (['cmd1'], Exception()),
+    )
+    def test_GitCommandError(self, init_args):
+        argv, cause = init_args
+        c = GitCommandError(argv, cause)
+        s = str(c)
+
+        self.assertIn(argv[0], s)
+        if cause:
+            self.assertIn(' failed due to: ', s)
+            self.assertIn(str(cause), s)
+        else:
+            self.assertIn(' failed!', s)
+
+    @ddt.data(
+        (['cmd1'], None),
+        (['cmd1'], "some cause"),
+        (['cmd1'], Exception()),
+    )
+    def test_HookExecutionError(self, init_args):
+        argv, cause = init_args
+        c = HookExecutionError(argv, cause)
+        s = str(c)
+
+        self.assertIn(argv[0], s)
+        if cause:
+            self.assertTrue(s.startswith('Hook('), s)
+            self.assertIn(str(cause), s)
+        else:
+            self.assertIn(' failed!', s)
diff --git a/git/test/test_git.py b/git/test/test_git.py
index b46ac72d..94614cd1 100644
--- a/git/test/test_git.py
+++ b/git/test/test_git.py
@@ -6,7 +6,6 @@
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 import os
 import sys
-import mock
 import subprocess
 
 from git.test.lib import (
@@ -22,11 +21,18 @@ from git import (
     Git,
     GitCommandError,
     GitCommandNotFound,
-    Repo
+    Repo,
+    cmd
 )
-from gitdb.test.lib import with_rw_directory
+from git.test.lib import with_rw_directory
 
-from git.compat import PY3
+from git.compat import PY3, is_darwin
+from git.util import finalize_process
+
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 
 class TestGit(TestBase):
@@ -36,6 +42,10 @@ class TestGit(TestBase):
         super(TestGit, cls).setUpClass()
         cls.git = Git(cls.rorepo.working_dir)
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     @patch.object(Git, 'execute')
     def test_call_process_calls_execute(self, git):
         git.return_value = ''
@@ -76,17 +86,16 @@ class TestGit(TestBase):
 
         # order is undefined
         res = self.git.transform_kwargs(**{'s': True, 't': True})
-        assert ['-s', '-t'] == res or ['-t', '-s'] == res
+        self.assertEqual(set(['-s', '-t']), set(res))
 
     def test_it_executes_git_to_shell_and_returns_result(self):
         assert_match('^git version [\d\.]{2}.*$', self.git.execute(["git", "version"]))
 
     def test_it_accepts_stdin(self):
         filename = fixture_path("cat_file_blob")
-        fh = open(filename, 'r')
-        assert_equal("70c379b63ffa0795fdbfbc128e5a2818397b7ef8",
-                     self.git.hash_object(istream=fh, stdin=True))
-        fh.close()
+        with open(filename, 'r') as fh:
+            assert_equal("70c379b63ffa0795fdbfbc128e5a2818397b7ef8",
+                         self.git.hash_object(istream=fh, stdin=True))
 
     @patch.object(Git, 'execute')
     def test_it_ignores_false_kwargs(self, git):
@@ -108,7 +117,7 @@ class TestGit(TestBase):
         g.stdin.write(b"b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
         g.stdin.flush()
         obj_info_two = g.stdout.readline()
-        assert obj_info == obj_info_two
+        self.assertEqual(obj_info, obj_info_two)
 
         # read data - have to read it in one large chunk
         size = int(obj_info.split()[2])
@@ -118,18 +127,19 @@ class TestGit(TestBase):
         # now we should be able to read a new object
         g.stdin.write(b"b2339455342180c7cc1e9bba3e9f181f7baa5167\n")
         g.stdin.flush()
-        assert g.stdout.readline() == obj_info
+        self.assertEqual(g.stdout.readline(), obj_info)
 
         # same can be achived using the respective command functions
         hexsha, typename, size = self.git.get_object_header(hexsha)
         hexsha, typename_two, size_two, data = self.git.get_object_data(hexsha)
-        assert typename == typename_two and size == size_two
+        self.assertEqual(typename, typename_two)
+        self.assertEqual(size, size_two)
 
     def test_version(self):
         v = self.git.version_info
-        assert isinstance(v, tuple)
+        self.assertIsInstance(v, tuple)
         for n in v:
-            assert isinstance(n, int)
+            self.assertIsInstance(n, int)
         # END verify number types
 
     def test_cmd_override(self):
@@ -164,36 +174,35 @@ class TestGit(TestBase):
 
     def test_env_vars_passed_to_git(self):
         editor = 'non_existant_editor'
-        with mock.patch.dict('os.environ', {'GIT_EDITOR': editor}):
-            assert self.git.var("GIT_EDITOR") == editor
+        with mock.patch.dict('os.environ', {'GIT_EDITOR': editor}):  # @UndefinedVariable
+            self.assertEqual(self.git.var("GIT_EDITOR"), editor)
 
     @with_rw_directory
     def test_environment(self, rw_dir):
         # sanity check
-        assert self.git.environment() == {}
+        self.assertEqual(self.git.environment(), {})
 
         # make sure the context manager works and cleans up after itself
         with self.git.custom_environment(PWD='/tmp'):
-            assert self.git.environment() == {'PWD': '/tmp'}
+            self.assertEqual(self.git.environment(), {'PWD': '/tmp'})
 
-        assert self.git.environment() == {}
+        self.assertEqual(self.git.environment(), {})
 
         old_env = self.git.update_environment(VARKEY='VARVALUE')
         # The returned dict can be used to revert the change, hence why it has
         # an entry with value 'None'.
-        assert old_env == {'VARKEY': None}
-        assert self.git.environment() == {'VARKEY': 'VARVALUE'}
+        self.assertEqual(old_env, {'VARKEY': None})
+        self.assertEqual(self.git.environment(), {'VARKEY': 'VARVALUE'})
 
         new_env = self.git.update_environment(**old_env)
-        assert new_env == {'VARKEY': 'VARVALUE'}
-        assert self.git.environment() == {}
+        self.assertEqual(new_env, {'VARKEY': 'VARVALUE'})
+        self.assertEqual(self.git.environment(), {})
 
         path = os.path.join(rw_dir, 'failing-script.sh')
-        stream = open(path, 'wt')
-        stream.write("#!/usr/bin/env sh\n" +
-                     "echo FOO\n")
-        stream.close()
-        os.chmod(path, 0o555)
+        with open(path, 'wt') as stream:
+            stream.write("#!/usr/bin/env sh\n"
+                         "echo FOO\n")
+        os.chmod(path, 0o777)
 
         rw_repo = Repo.init(os.path.join(rw_dir, 'repo'))
         remote = rw_repo.create_remote('ssh-origin', "ssh://git@server/foo")
@@ -205,14 +214,11 @@ class TestGit(TestBase):
                 try:
                     remote.fetch()
                 except GitCommandError as err:
-                    if sys.version_info[0] < 3 and sys.platform == 'darwin':
-                        assert 'ssh-origin' in str(err)
-                        assert err.status == 128
+                    if sys.version_info[0] < 3 and is_darwin:
+                        self.assertIn('ssh-orig, ' in str(err))
+                        self.assertEqual(err.status, 128)
                     else:
-                        assert 'FOO' in str(err)
-                # end
-            # end
-        # end if select.poll exists
+                        self.assertIn('FOO', str(err))
 
     def test_handle_process_output(self):
         from git.cmd import handle_process_output
@@ -226,13 +232,16 @@ class TestGit(TestBase):
         def counter_stderr(line):
             count[2] += 1
 
-        proc = subprocess.Popen([sys.executable, fixture_path('cat_file.py'), str(fixture_path('issue-301_stderr'))],
+        cmdline = [sys.executable, fixture_path('cat_file.py'), str(fixture_path('issue-301_stderr'))]
+        proc = subprocess.Popen(cmdline,
                                 stdin=None,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE,
-                                shell=False)
+                                shell=False,
+                                creationflags=cmd.PROC_CREATIONFLAGS,
+                                )
 
-        handle_process_output(proc, counter_stdout, counter_stderr, lambda proc: proc.wait())
+        handle_process_output(proc, counter_stdout, counter_stderr, finalize_process)
 
-        assert count[1] == line_count
-        assert count[2] == line_count
+        self.assertEqual(count[1], line_count)
+        self.assertEqual(count[2], line_count)
diff --git a/git/test/test_index.py b/git/test/test_index.py
index 178a59d2..1ffbe9e2 100644
--- a/git/test/test_index.py
+++ b/git/test/test_index.py
@@ -11,7 +11,7 @@ from git.test.lib import (
     fixture,
     with_rw_repo
 )
-from git.util import Actor
+from git.util import Actor, rmtree
 from git.exc import (
     HookExecutionError,
     InvalidGitRepositoryError
@@ -27,12 +27,11 @@ from git import (
     GitCommandError,
     CheckoutError,
 )
-from git.compat import string_types
+from git.compat import string_types, is_win
 from gitdb.util import hex_to_bin
 import os
 import sys
 import tempfile
-import shutil
 from stat import (
     S_ISLNK,
     ST_MODE
@@ -46,7 +45,7 @@ from git.index.typ import (
     IndexEntry
 )
 from git.index.fun import hook_path
-from gitdb.test.lib import with_rw_directory
+from git.test.lib import with_rw_directory
 
 
 class TestIndex(TestBase):
@@ -56,9 +55,9 @@ class TestIndex(TestBase):
         self._reset_progress()
 
     def _assert_fprogress(self, entries):
-        assert len(entries) == len(self._fprogress_map)
+        self.assertEqual(len(entries), len(self._fprogress_map))
         for path, call_count in self._fprogress_map.items():
-            assert call_count == 2
+            self.assertEqual(call_count, 2)
         # END for each item in progress map
         self._reset_progress()
 
@@ -108,15 +107,14 @@ class TestIndex(TestBase):
 
         # test stage
         index_merge = IndexFile(self.rorepo, fixture_path("index_merge"))
-        assert len(index_merge.entries) == 106
+        self.assertEqual(len(index_merge.entries), 106)
         assert len(list(e for e in index_merge.entries.values() if e.stage != 0))
 
         # write the data - it must match the original
         tmpfile = tempfile.mktemp()
         index_merge.write(tmpfile)
-        fp = open(tmpfile, 'rb')
-        assert fp.read() == fixture("index_merge")
-        fp.close()
+        with open(tmpfile, 'rb') as fp:
+            self.assertEqual(fp.read(), fixture("index_merge"))
         os.remove(tmpfile)
 
     def _cmp_tree_index(self, tree, index):
@@ -135,7 +133,7 @@ class TestIndex(TestBase):
             raise AssertionError("CMP Failed: Missing entries in index: %s, missing in tree: %s" %
                                  (bset - iset, iset - bset))
         # END assertion message
-        
+
     @with_rw_repo('0.1.6')
     def test_index_lock_handling(self, rw_repo):
         def add_bad_blob():
@@ -147,7 +145,8 @@ class TestIndex(TestBase):
         except Exception as ex:
             msg_py3 = "required argument is not an integer"
             msg_py2 = "cannot convert argument to integer"
-            assert msg_py2 in str(ex) or msg_py3 in str(ex)
+            ## msg_py26 ="unsupported operand type(s) for &: 'str' and 'long'"
+            assert msg_py2 in str(ex) or msg_py3 in str(ex), str(ex)
 
         ## 2nd time should not fail due to stray lock file
         try:
@@ -157,6 +156,9 @@ class TestIndex(TestBase):
 
     @with_rw_repo('0.1.6')
     def test_index_file_from_tree(self, rw_repo):
+        if sys.version_info < (2, 7):
+            ## Skipped, not `assertRaisesRegexp` in py2.6
+            return
         common_ancestor_sha = "5117c9c8a4d3af19a9958677e45cda9269de1541"
         cur_sha = "4b43ca7ff72d5f535134241e7c797ddc9c7a3573"
         other_sha = "39f85c4358b7346fee22169da9cad93901ea9eb9"
@@ -203,13 +205,13 @@ class TestIndex(TestBase):
             assert (blob.path, 0) in three_way_index.entries
             num_blobs += 1
         # END for each blob
-        assert num_blobs == len(three_way_index.entries)
+        self.assertEqual(num_blobs, len(three_way_index.entries))
 
     @with_rw_repo('0.1.6')
     def test_index_merge_tree(self, rw_repo):
         # A bit out of place, but we need a different repo for this:
-        assert self.rorepo != rw_repo and not (self.rorepo == rw_repo)
-        assert len(set((self.rorepo, self.rorepo, rw_repo, rw_repo))) == 2
+        self.assertNotEqual(self.rorepo, rw_repo)
+        self.assertEqual(len(set((self.rorepo, self.rorepo, rw_repo, rw_repo))), 2)
 
         # SINGLE TREE MERGE
         # current index is at the (virtual) cur_commit
@@ -222,7 +224,7 @@ class TestIndex(TestBase):
         assert manifest_entry.binsha != rw_repo.index.entries[manifest_key].binsha
 
         rw_repo.index.reset(rw_repo.head)
-        assert rw_repo.index.entries[manifest_key].binsha == manifest_entry.binsha
+        self.assertEqual(rw_repo.index.entries[manifest_key].binsha, manifest_entry.binsha)
 
         # FAKE MERGE
         #############
@@ -240,7 +242,7 @@ class TestIndex(TestBase):
         index = rw_repo.index
         index.entries[manifest_key] = IndexEntry.from_base(manifest_fake_entry)
         index.write()
-        assert rw_repo.index.entries[manifest_key].hexsha == Diff.NULL_HEX_SHA
+        self.assertEqual(rw_repo.index.entries[manifest_key].hexsha, Diff.NULL_HEX_SHA)
 
         # write an unchanged index ( just for the fun of it )
         rw_repo.index.write()
@@ -264,7 +266,8 @@ class TestIndex(TestBase):
         # now make a proper three way merge with unmerged entries
         unmerged_tree = IndexFile.from_tree(rw_repo, parent_commit, tree, next_commit)
         unmerged_blobs = unmerged_tree.unmerged_blobs()
-        assert len(unmerged_blobs) == 1 and list(unmerged_blobs.keys())[0] == manifest_key[0]
+        self.assertEqual(len(unmerged_blobs), 1)
+        self.assertEqual(list(unmerged_blobs.keys())[0], manifest_key[0])
 
     @with_rw_repo('0.1.6')
     def test_index_file_diffing(self, rw_repo):
@@ -286,11 +289,11 @@ class TestIndex(TestBase):
 
         # diff against same index is 0
         diff = index.diff()
-        assert len(diff) == 0
+        self.assertEqual(len(diff), 0)
 
         # against HEAD as string, must be the same as it matches index
         diff = index.diff('HEAD')
-        assert len(diff) == 0
+        self.assertEqual(len(diff), 0)
 
         # against previous head, there must be a difference
         diff = index.diff(cur_head_commit)
@@ -300,7 +303,7 @@ class TestIndex(TestBase):
         adiff = index.diff(str(cur_head_commit), R=True)
         odiff = index.diff(cur_head_commit, R=False)    # now its not reversed anymore
         assert adiff != odiff
-        assert odiff == diff                    # both unreversed diffs against HEAD
+        self.assertEqual(odiff, diff)                    # both unreversed diffs against HEAD
 
         # against working copy - its still at cur_commit
         wdiff = index.diff(None)
@@ -316,8 +319,8 @@ class TestIndex(TestBase):
         rev_head_parent = 'HEAD~1'
         assert index.reset(rev_head_parent) is index
 
-        assert cur_branch == rw_repo.active_branch
-        assert cur_commit == rw_repo.head.commit
+        self.assertEqual(cur_branch, rw_repo.active_branch)
+        self.assertEqual(cur_commit, rw_repo.head.commit)
 
         # there must be differences towards the working tree which is in the 'future'
         assert index.diff(None)
@@ -325,22 +328,19 @@ class TestIndex(TestBase):
         # reset the working copy as well to current head,to pull 'back' as well
         new_data = b"will be reverted"
         file_path = os.path.join(rw_repo.working_tree_dir, "CHANGES")
-        fp = open(file_path, "wb")
-        fp.write(new_data)
-        fp.close()
+        with open(file_path, "wb") as fp:
+            fp.write(new_data)
         index.reset(rev_head_parent, working_tree=True)
         assert not index.diff(None)
-        assert cur_branch == rw_repo.active_branch
-        assert cur_commit == rw_repo.head.commit
-        fp = open(file_path, 'rb')
-        try:
+        self.assertEqual(cur_branch, rw_repo.active_branch)
+        self.assertEqual(cur_commit, rw_repo.head.commit)
+        with open(file_path, 'rb') as fp:
             assert fp.read() != new_data
-        finally:
-            fp.close()
 
         # test full checkout
         test_file = os.path.join(rw_repo.working_tree_dir, "CHANGES")
-        open(test_file, 'ab').write(b"some data")
+        with open(test_file, 'ab') as fd:
+            fd.write(b"some data")
         rval = index.checkout(None, force=True, fprogress=self._fprogress)
         assert 'CHANGES' in list(rval)
         self._assert_fprogress([None])
@@ -355,7 +355,7 @@ class TestIndex(TestBase):
         # individual file
         os.remove(test_file)
         rval = index.checkout(test_file, fprogress=self._fprogress)
-        assert list(rval)[0] == 'CHANGES'
+        self.assertEqual(list(rval)[0], 'CHANGES')
         self._assert_fprogress([test_file])
         assert os.path.exists(test_file)
 
@@ -365,16 +365,19 @@ class TestIndex(TestBase):
 
         # checkout file with modifications
         append_data = b"hello"
-        fp = open(test_file, "ab")
-        fp.write(append_data)
-        fp.close()
+        with open(test_file, "ab") as fp:
+            fp.write(append_data)
         try:
             index.checkout(test_file)
         except CheckoutError as e:
-            assert len(e.failed_files) == 1 and e.failed_files[0] == os.path.basename(test_file)
-            assert (len(e.failed_files) == len(e.failed_reasons)) and isinstance(e.failed_reasons[0], string_types)
-            assert len(e.valid_files) == 0
-            assert open(test_file, 'rb').read().endswith(append_data)
+            self.assertEqual(len(e.failed_files), 1)
+            self.assertEqual(e.failed_files[0], os.path.basename(test_file))
+            self.assertEqual(len(e.failed_files), len(e.failed_reasons))
+            self.assertIsInstance(e.failed_reasons[0], string_types)
+            self.assertEqual(len(e.valid_files), 0)
+            with open(test_file, 'rb') as fd:
+                s = fd.read()
+            self.assertTrue(s.endswith(append_data), s)
         else:
             raise AssertionError("Exception CheckoutError not thrown")
 
@@ -383,7 +386,7 @@ class TestIndex(TestBase):
         assert not open(test_file, 'rb').read().endswith(append_data)
 
         # checkout directory
-        shutil.rmtree(os.path.join(rw_repo.working_tree_dir, "lib"))
+        rmtree(os.path.join(rw_repo.working_tree_dir, "lib"))
         rval = index.checkout('lib')
         assert len(list(rval)) > 1
 
@@ -411,7 +414,7 @@ class TestIndex(TestBase):
         writer.set_value("user", "name", uname)
         writer.set_value("user", "email", umail)
         writer.release()
-        assert writer.get_value("user", "name") == uname
+        self.assertEqual(writer.get_value("user", "name"), uname)
 
         # remove all of the files, provide a wild mix of paths, BaseIndexEntries,
         # IndexEntries
@@ -434,21 +437,21 @@ class TestIndex(TestBase):
         # END mixed iterator
         deleted_files = index.remove(mixed_iterator(), working_tree=False)
         assert deleted_files
-        assert self._count_existing(rw_repo, deleted_files) == len(deleted_files)
-        assert len(index.entries) == 0
+        self.assertEqual(self._count_existing(rw_repo, deleted_files), len(deleted_files))
+        self.assertEqual(len(index.entries), 0)
 
         # reset the index to undo our changes
         index.reset()
-        assert len(index.entries) == num_entries
+        self.assertEqual(len(index.entries), num_entries)
 
         # remove with working copy
         deleted_files = index.remove(mixed_iterator(), working_tree=True)
         assert deleted_files
-        assert self._count_existing(rw_repo, deleted_files) == 0
+        self.assertEqual(self._count_existing(rw_repo, deleted_files), 0)
 
         # reset everything
         index.reset(working_tree=True)
-        assert self._count_existing(rw_repo, deleted_files) == len(deleted_files)
+        self.assertEqual(self._count_existing(rw_repo, deleted_files), len(deleted_files))
 
         # invalid type
         self.failUnlessRaises(TypeError, index.remove, [1])
@@ -465,14 +468,14 @@ class TestIndex(TestBase):
 
         new_commit = index.commit(commit_message, head=False)
         assert cur_commit != new_commit
-        assert new_commit.author.name == uname
-        assert new_commit.author.email == umail
-        assert new_commit.committer.name == uname
-        assert new_commit.committer.email == umail
-        assert new_commit.message == commit_message
-        assert new_commit.parents[0] == cur_commit
-        assert len(new_commit.parents) == 1
-        assert cur_head.commit == cur_commit
+        self.assertEqual(new_commit.author.name, uname)
+        self.assertEqual(new_commit.author.email, umail)
+        self.assertEqual(new_commit.committer.name, uname)
+        self.assertEqual(new_commit.committer.email, umail)
+        self.assertEqual(new_commit.message, commit_message)
+        self.assertEqual(new_commit.parents[0], cur_commit)
+        self.assertEqual(len(new_commit.parents), 1)
+        self.assertEqual(cur_head.commit, cur_commit)
 
         # commit with other actor
         cur_commit = cur_head.commit
@@ -481,15 +484,15 @@ class TestIndex(TestBase):
         my_committer = Actor(u"Committing Frèderic Çaufl€", "committer@example.com")
         commit_actor = index.commit(commit_message, author=my_author, committer=my_committer)
         assert cur_commit != commit_actor
-        assert commit_actor.author.name == u"Frèderic Çaufl€"
-        assert commit_actor.author.email == "author@example.com"
-        assert commit_actor.committer.name == u"Committing Frèderic Çaufl€"
-        assert commit_actor.committer.email == "committer@example.com"
-        assert commit_actor.message == commit_message
-        assert commit_actor.parents[0] == cur_commit
-        assert len(new_commit.parents) == 1
-        assert cur_head.commit == commit_actor
-        assert cur_head.log()[-1].actor == my_committer
+        self.assertEqual(commit_actor.author.name, u"Frèderic Çaufl€")
+        self.assertEqual(commit_actor.author.email, "author@example.com")
+        self.assertEqual(commit_actor.committer.name, u"Committing Frèderic Çaufl€")
+        self.assertEqual(commit_actor.committer.email, "committer@example.com")
+        self.assertEqual(commit_actor.message, commit_message)
+        self.assertEqual(commit_actor.parents[0], cur_commit)
+        self.assertEqual(len(new_commit.parents), 1)
+        self.assertEqual(cur_head.commit, commit_actor)
+        self.assertEqual(cur_head.log()[-1].actor, my_committer)
 
         # commit with author_date and commit_date
         cur_commit = cur_head.commit
@@ -498,25 +501,25 @@ class TestIndex(TestBase):
         new_commit = index.commit(commit_message, author_date="2006-04-07T22:13:13", commit_date="2005-04-07T22:13:13")
         assert cur_commit != new_commit
         print(new_commit.authored_date, new_commit.committed_date)
-        assert new_commit.message == commit_message
-        assert new_commit.authored_date == 1144447993
-        assert new_commit.committed_date == 1112911993
+        self.assertEqual(new_commit.message, commit_message)
+        self.assertEqual(new_commit.authored_date, 1144447993)
+        self.assertEqual(new_commit.committed_date, 1112911993)
 
         # same index, no parents
         commit_message = "index without parents"
         commit_no_parents = index.commit(commit_message, parent_commits=list(), head=True)
-        assert commit_no_parents.message == commit_message
-        assert len(commit_no_parents.parents) == 0
-        assert cur_head.commit == commit_no_parents
+        self.assertEqual(commit_no_parents.message, commit_message)
+        self.assertEqual(len(commit_no_parents.parents), 0)
+        self.assertEqual(cur_head.commit, commit_no_parents)
 
         # same index, multiple parents
         commit_message = "Index with multiple parents\n    commit with another line"
         commit_multi_parent = index.commit(commit_message, parent_commits=(commit_no_parents, new_commit))
-        assert commit_multi_parent.message == commit_message
-        assert len(commit_multi_parent.parents) == 2
-        assert commit_multi_parent.parents[0] == commit_no_parents
-        assert commit_multi_parent.parents[1] == new_commit
-        assert cur_head.commit == commit_multi_parent
+        self.assertEqual(commit_multi_parent.message, commit_message)
+        self.assertEqual(len(commit_multi_parent.parents), 2)
+        self.assertEqual(commit_multi_parent.parents[0], commit_no_parents)
+        self.assertEqual(commit_multi_parent.parents[1], new_commit)
+        self.assertEqual(cur_head.commit, commit_multi_parent)
 
         # re-add all files in lib
         # get the lib folder back on disk, but get an index without it
@@ -535,17 +538,17 @@ class TestIndex(TestBase):
         entries = index.reset(new_commit).add([os.path.join('lib', 'git', '*.py')], fprogress=self._fprogress_add)
         self._assert_entries(entries)
         self._assert_fprogress(entries)
-        assert len(entries) == 14
+        self.assertEqual(len(entries), 14)
 
         # same file
         entries = index.reset(new_commit).add(
             [os.path.join(rw_repo.working_tree_dir, 'lib', 'git', 'head.py')] * 2, fprogress=self._fprogress_add)
         self._assert_entries(entries)
-        assert entries[0].mode & 0o644 == 0o644
+        self.assertEqual(entries[0].mode & 0o644, 0o644)
         # would fail, test is too primitive to handle this case
         # self._assert_fprogress(entries)
         self._reset_progress()
-        assert len(entries) == 2
+        self.assertEqual(len(entries), 2)
 
         # missing path
         self.failUnlessRaises(OSError, index.reset(new_commit).add, ['doesnt/exist/must/raise'])
@@ -555,7 +558,8 @@ class TestIndex(TestBase):
         entries = index.reset(new_commit).add([old_blob], fprogress=self._fprogress_add)
         self._assert_entries(entries)
         self._assert_fprogress(entries)
-        assert index.entries[(old_blob.path, 0)].hexsha == old_blob.hexsha and len(entries) == 1
+        self.assertEqual(index.entries[(old_blob.path, 0)].hexsha, old_blob.hexsha)
+        self.assertEqual(len(entries), 1)
 
         # mode 0 not allowed
         null_hex_sha = Diff.NULL_HEX_SHA
@@ -570,23 +574,25 @@ class TestIndex(TestBase):
             [BaseIndexEntry((0o10644, null_bin_sha, 0, new_file_relapath))], fprogress=self._fprogress_add)
         self._assert_entries(entries)
         self._assert_fprogress(entries)
-        assert len(entries) == 1 and entries[0].hexsha != null_hex_sha
+        self.assertEqual(len(entries), 1)
+        self.assertNotEquals(entries[0].hexsha, null_hex_sha)
 
         # add symlink
-        if sys.platform != "win32":
+        if not is_win:
             for target in ('/etc/nonexisting', '/etc/passwd', '/etc'):
                 basename = "my_real_symlink"
-                
+
                 link_file = os.path.join(rw_repo.working_tree_dir, basename)
                 os.symlink(target, link_file)
                 entries = index.reset(new_commit).add([link_file], fprogress=self._fprogress_add)
                 self._assert_entries(entries)
                 self._assert_fprogress(entries)
-                assert len(entries) == 1 and S_ISLNK(entries[0].mode)
-                assert S_ISLNK(index.entries[index.entry_key("my_real_symlink", 0)].mode)
+                self.assertEqual(len(entries), 1)
+                self.assertTrue(S_ISLNK(entries[0].mode))
+                self.assertTrue(S_ISLNK(index.entries[index.entry_key("my_real_symlink", 0)].mode))
 
                 # we expect only the target to be written
-                assert index.repo.odb.stream(entries[0].binsha).read().decode('ascii') == target
+                self.assertEqual(index.repo.odb.stream(entries[0].binsha).read().decode('ascii'), target)
 
                 os.remove(link_file)
             # end for each target
@@ -601,7 +607,8 @@ class TestIndex(TestBase):
         self._assert_entries(entries)
         self._assert_fprogress(entries)
         assert entries[0].hexsha != null_hex_sha
-        assert len(entries) == 1 and S_ISLNK(entries[0].mode)
+        self.assertEqual(len(entries), 1)
+        self.assertTrue(S_ISLNK(entries[0].mode))
 
         # assure this also works with an alternate method
         full_index_entry = IndexEntry.from_base(BaseIndexEntry((0o120000, entries[0].binsha, 0, entries[0].path)))
@@ -626,12 +633,13 @@ class TestIndex(TestBase):
         index.checkout(fake_symlink_path)
 
         # on windows we will never get symlinks
-        if os.name == 'nt':
+        if is_win:
             # simlinks should contain the link as text ( which is what a
             # symlink actually is )
-            open(fake_symlink_path, 'rb').read() == link_target
+            with open(fake_symlink_path, 'rt') as fd:
+                self.assertEqual(fd.read(), link_target)
         else:
-            assert S_ISLNK(os.lstat(fake_symlink_path)[ST_MODE])
+            self.assertTrue(S_ISLNK(os.lstat(fake_symlink_path)[ST_MODE]))
 
         # TEST RENAMING
         def assert_mv_rval(rval):
@@ -651,7 +659,7 @@ class TestIndex(TestBase):
         # files into directory - dry run
         paths = ['LICENSE', 'VERSION', 'doc']
         rval = index.move(paths, dry_run=True)
-        assert len(rval) == 2
+        self.assertEqual(len(rval), 2)
         assert os.path.exists(paths[0])
 
         # again, no dry run
@@ -681,7 +689,8 @@ class TestIndex(TestBase):
 
             for fid in range(3):
                 fname = 'newfile%i' % fid
-                open(fname, 'wb').write(b"abcd")
+                with open(fname, 'wb') as fd:
+                    fd.write(b"abcd")
                 yield Blob(rw_repo, Blob.NULL_BIN_SHA, 0o100644, fname)
             # END for each new file
         # END path producer
@@ -707,7 +716,7 @@ class TestIndex(TestBase):
             assert fkey not in index.entries
 
         index.add(files, write=True)
-        if os.name != 'nt':
+        if is_win:
             hp = hook_path('pre-commit', index.repo.git_dir)
             hpd = os.path.dirname(hp)
             if not os.path.isdir(hpd):
@@ -715,15 +724,22 @@ class TestIndex(TestBase):
             with open(hp, "wt") as fp:
                 fp.write("#!/usr/bin/env sh\necho stdout; echo stderr 1>&2; exit 1")
             # end
-            os.chmod(hp, 0o544)
+            os.chmod(hp, 0o744)
             try:
                 index.commit("This should fail")
             except HookExecutionError as err:
-                assert err.status == 1
-                assert err.command == hp
-                assert err.stdout == 'stdout\n'
-                assert err.stderr == 'stderr\n'
-                assert str(err)
+                if is_win:
+                    self.assertIsInstance(err.status, OSError)
+                    self.assertEqual(err.command, [hp])
+                    self.assertEqual(err.stdout, '')
+                    self.assertEqual(err.stderr, '')
+                    assert str(err)
+                else:
+                    self.assertEqual(err.status, 1)
+                    self.assertEqual(err.command, hp)
+                    self.assertEqual(err.stdout, 'stdout\n')
+                    self.assertEqual(err.stderr, 'stderr\n')
+                    assert str(err)
             else:
                 raise AssertionError("Should have cought a HookExecutionError")
             # end exception handling
@@ -763,7 +779,7 @@ class TestIndex(TestBase):
             count += 1
             index = rw_repo.index.reset(commit)
             orig_tree = commit.tree
-            assert index.write_tree() == orig_tree
+            self.assertEqual(index.write_tree(), orig_tree)
         # END for each commit
 
     def test_index_new(self):
diff --git a/git/test/test_reflog.py b/git/test/test_reflog.py
index 3571e083..dffedf3b 100644
--- a/git/test/test_reflog.py
+++ b/git/test/test_reflog.py
@@ -7,11 +7,10 @@ from git.refs import (
     RefLogEntry,
     RefLog
 )
-from git.util import Actor
+from git.util import Actor, rmtree
 from gitdb.util import hex_to_bin
 
 import tempfile
-import shutil
 import os
 
 
@@ -104,4 +103,4 @@ class TestRefLog(TestBase):
         # END for each reflog
 
         # finally remove our temporary data
-        shutil.rmtree(tdir)
+        rmtree(tdir)
diff --git a/git/test/test_remote.py b/git/test/test_remote.py
index 3c2e622d..b99e49cf 100644
--- a/git/test/test_remote.py
+++ b/git/test/test_remote.py
@@ -25,10 +25,9 @@ from git import (
     Remote,
     GitCommandError
 )
-from git.util import IterableList
+from git.util import IterableList, rmtree
 from git.compat import string_types
 import tempfile
-import shutil
 import os
 import random
 
@@ -101,9 +100,13 @@ class TestRemoteProgress(RemoteProgress):
 
 class TestRemote(TestBase):
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     def _print_fetchhead(self, repo):
-        fp = open(os.path.join(repo.git_dir, "FETCH_HEAD"))
-        fp.close()
+        with open(os.path.join(repo.git_dir, "FETCH_HEAD")):
+            pass
 
     def _do_test_fetch_result(self, results, remote):
         # self._print_fetchhead(remote.repo)
@@ -281,7 +284,7 @@ class TestRemote(TestBase):
             # and only provides progress information to ttys
             res = fetch_and_test(other_origin)
         finally:
-            shutil.rmtree(other_repo_dir)
+            rmtree(other_repo_dir)
         # END test and cleanup
 
     def _assert_push_and_pull(self, remote, rw_repo, remote_repo):
@@ -403,7 +406,7 @@ class TestRemote(TestBase):
 
             # OPTIONS
             # cannot use 'fetch' key anymore as it is now a method
-            for opt in ("url", ):
+            for opt in ("url",):
                 val = getattr(remote, opt)
                 reader = remote.config_reader
                 assert reader.get(opt) == val
diff --git a/git/test/test_repo.py b/git/test/test_repo.py
index d04a0f66..349d955e 100644
--- a/git/test/test_repo.py
+++ b/git/test/test_repo.py
@@ -4,18 +4,15 @@
 #
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
+import glob
+from io import BytesIO
+import itertools
+import functools as fnt
+import os
 import pickle
+import sys
+import tempfile
 
-from git.test.lib import (
-    patch,
-    TestBase,
-    with_rw_repo,
-    fixture,
-    assert_false,
-    assert_equal,
-    assert_true,
-    raises
-)
 from git import (
     InvalidGitRepositoryError,
     Repo,
@@ -33,24 +30,33 @@ from git import (
     BadName,
     GitCommandError
 )
-from git.repo.fun import touch
-from git.util import join_path_native
+from git.compat import (
+    PY3,
+    is_win,
+    string_types,
+    win_encode,
+)
 from git.exc import (
     BadObject,
 )
+from git.repo.fun import touch
+from git.test.lib import (
+    patch,
+    TestBase,
+    with_rw_repo,
+    fixture,
+    assert_false,
+    assert_equal,
+    assert_true,
+    raises
+)
+from git.test.lib import with_rw_directory
+from git.util import join_path_native, rmtree, rmfile
 from gitdb.util import bin_to_hex
-from git.compat import string_types
-from gitdb.test.lib import with_rw_directory
-
-import os
-import sys
-import tempfile
-import shutil
-import itertools
-from io import BytesIO
-
 from nose import SkipTest
 
+import os.path as osp
+
 
 def iter_flatten(lol):
     for items in lol:
@@ -62,8 +68,26 @@ def flatten(lol):
     return list(iter_flatten(lol))
 
 
+_tc_lock_fpaths = osp.join(osp.dirname(__file__), '../../.git/*.lock')
+
+
+def _rm_lock_files():
+    for lfp in glob.glob(_tc_lock_fpaths):
+        rmfile(lfp)
+
+
 class TestRepo(TestBase):
 
+    def setUp(self):
+        _rm_lock_files()
+
+    def tearDown(self):
+        for lfp in glob.glob(_tc_lock_fpaths):
+            if osp.isfile(lfp):
+                raise AssertionError('Previous TC left hanging git-lock file: %s', lfp)
+        import gc
+        gc.collect()
+
     @raises(InvalidGitRepositoryError)
     def test_new_should_raise_on_invalid_repo_location(self):
         Repo(tempfile.gettempdir())
@@ -75,10 +99,10 @@ class TestRepo(TestBase):
     @with_rw_repo('0.3.2.1')
     def test_repo_creation_from_different_paths(self, rw_repo):
         r_from_gitdir = Repo(rw_repo.git_dir)
-        assert r_from_gitdir.git_dir == rw_repo.git_dir
+        self.assertEqual(r_from_gitdir.git_dir, rw_repo.git_dir)
         assert r_from_gitdir.git_dir.endswith('.git')
         assert not rw_repo.git.working_dir.endswith('.git')
-        assert r_from_gitdir.git.working_dir == rw_repo.git.working_dir
+        self.assertEqual(r_from_gitdir.git.working_dir, rw_repo.git.working_dir)
 
     def test_description(self):
         txt = "Test repository"
@@ -92,33 +116,33 @@ class TestRepo(TestBase):
     def test_heads_should_populate_head_data(self):
         for head in self.rorepo.heads:
             assert head.name
-            assert isinstance(head.commit, Commit)
+            self.assertIsInstance(head.commit, Commit)
         # END for each head
 
-        assert isinstance(self.rorepo.heads.master, Head)
-        assert isinstance(self.rorepo.heads['master'], Head)
+        self.assertIsInstance(self.rorepo.heads.master, Head)
+        self.assertIsInstance(self.rorepo.heads['master'], Head)
 
     def test_tree_from_revision(self):
         tree = self.rorepo.tree('0.1.6')
-        assert len(tree.hexsha) == 40
-        assert tree.type == "tree"
-        assert self.rorepo.tree(tree) == tree
+        self.assertEqual(len(tree.hexsha), 40)
+        self.assertEqual(tree.type, "tree")
+        self.assertEqual(self.rorepo.tree(tree), tree)
 
         # try from invalid revision that does not exist
         self.failUnlessRaises(BadName, self.rorepo.tree, 'hello world')
-        
+
     def test_pickleable(self):
         pickle.loads(pickle.dumps(self.rorepo))
 
     def test_commit_from_revision(self):
         commit = self.rorepo.commit('0.1.4')
-        assert commit.type == 'commit'
-        assert self.rorepo.commit(commit) == commit
+        self.assertEqual(commit.type, 'commit')
+        self.assertEqual(self.rorepo.commit(commit), commit)
 
     def test_commits(self):
         mc = 10
         commits = list(self.rorepo.iter_commits('0.1.6', max_count=mc))
-        assert len(commits) == mc
+        self.assertEqual(len(commits), mc)
 
         c = commits[0]
         assert_equal('9a4b1d4d11eee3c5362a4152216376e634bd14cf', c.hexsha)
@@ -135,23 +159,23 @@ class TestRepo(TestBase):
         assert_equal("Bumped version 0.1.6\n", c.message)
 
         c = commits[1]
-        assert isinstance(c.parents, tuple)
+        self.assertIsInstance(c.parents, tuple)
 
     def test_trees(self):
         mc = 30
         num_trees = 0
         for tree in self.rorepo.iter_trees('0.1.5', max_count=mc):
             num_trees += 1
-            assert isinstance(tree, Tree)
+            self.assertIsInstance(tree, Tree)
         # END for each tree
-        assert num_trees == mc
+        self.assertEqual(num_trees, mc)
 
     def _assert_empty_repo(self, repo):
         # test all kinds of things with an empty, freshly initialized repo.
         # It should throw good errors
 
         # entries should be empty
-        assert len(repo.index.entries) == 0
+        self.assertEqual(len(repo.index.entries), 0)
 
         # head is accessible
         assert repo.head
@@ -183,7 +207,7 @@ class TestRepo(TestBase):
             # with specific path
             for path in (git_dir_rela, git_dir_abs):
                 r = Repo.init(path=path, bare=True)
-                assert isinstance(r, Repo)
+                self.assertIsInstance(r, Repo)
                 assert r.bare is True
                 assert not r.has_separate_working_tree()
                 assert os.path.isdir(r.git_dir)
@@ -196,7 +220,7 @@ class TestRepo(TestBase):
                 self._assert_empty_repo(rc)
 
                 try:
-                    shutil.rmtree(clone_path)
+                    rmtree(clone_path)
                 except OSError:
                     # when relative paths are used, the clone may actually be inside
                     # of the parent directory
@@ -207,9 +231,9 @@ class TestRepo(TestBase):
                 rc = Repo.clone_from(r.git_dir, clone_path)
                 self._assert_empty_repo(rc)
 
-                shutil.rmtree(git_dir_abs)
+                rmtree(git_dir_abs)
                 try:
-                    shutil.rmtree(clone_path)
+                    rmtree(clone_path)
                 except OSError:
                     # when relative paths are used, the clone may actually be inside
                     # of the parent directory
@@ -227,7 +251,7 @@ class TestRepo(TestBase):
             self._assert_empty_repo(r)
         finally:
             try:
-                shutil.rmtree(del_dir_abs)
+                rmtree(del_dir_abs)
             except OSError:
                 pass
             os.chdir(prev_cwd)
@@ -239,18 +263,18 @@ class TestRepo(TestBase):
     def test_daemon_export(self):
         orig_val = self.rorepo.daemon_export
         self.rorepo.daemon_export = not orig_val
-        assert self.rorepo.daemon_export == (not orig_val)
+        self.assertEqual(self.rorepo.daemon_export, (not orig_val))
         self.rorepo.daemon_export = orig_val
-        assert self.rorepo.daemon_export == orig_val
+        self.assertEqual(self.rorepo.daemon_export, orig_val)
 
     def test_alternates(self):
         cur_alternates = self.rorepo.alternates
         # empty alternates
         self.rorepo.alternates = []
-        assert self.rorepo.alternates == []
+        self.assertEqual(self.rorepo.alternates, [])
         alts = ["other/location", "this/location"]
         self.rorepo.alternates = alts
-        assert alts == self.rorepo.alternates
+        self.assertEqual(alts, self.rorepo.alternates)
         self.rorepo.alternates = cur_alternates
 
     def test_repr(self):
@@ -295,25 +319,27 @@ class TestRepo(TestBase):
         assert rwrepo.is_dirty(untracked_files=True, path="doc") is True
 
     def test_head(self):
-        assert self.rorepo.head.reference.object == self.rorepo.active_branch.object
+        self.assertEqual(self.rorepo.head.reference.object, self.rorepo.active_branch.object)
 
     def test_index(self):
         index = self.rorepo.index
-        assert isinstance(index, IndexFile)
+        self.assertIsInstance(index, IndexFile)
 
     def test_tag(self):
         assert self.rorepo.tag('refs/tags/0.1.5').commit
 
     def test_archive(self):
         tmpfile = tempfile.mktemp(suffix='archive-test')
-        stream = open(tmpfile, 'wb')
-        self.rorepo.archive(stream, '0.1.6', path='doc')
-        assert stream.tell()
-        stream.close()
+        with open(tmpfile, 'wb') as stream:
+            self.rorepo.archive(stream, '0.1.6', path='doc')
+            assert stream.tell()
         os.remove(tmpfile)
 
     @patch.object(Git, '_call_process')
     def test_should_display_blame_information(self, git):
+        if sys.version_info < (2, 7):
+            ## Skipped, not `assertRaisesRegexp` in py2.6
+            return
         git.return_value = fixture('blame')
         b = self.rorepo.blame('master', 'lib/git.py')
         assert_equal(13, len(b))
@@ -341,7 +367,7 @@ class TestRepo(TestBase):
         # BINARY BLAME
         git.return_value = fixture('blame_binary')
         blames = self.rorepo.blame('master', 'rps')
-        assert len(blames) == 2
+        self.assertEqual(len(blames), 2)
 
     def test_blame_real(self):
         c = 0
@@ -361,32 +387,35 @@ class TestRepo(TestBase):
         git.return_value = fixture('blame_incremental')
         blame_output = self.rorepo.blame_incremental('9debf6b0aafb6f7781ea9d1383c86939a1aacde3', 'AUTHORS')
         blame_output = list(blame_output)
-        assert len(blame_output) == 5
+        self.assertEqual(len(blame_output), 5)
 
         # Check all outputted line numbers
         ranges = flatten([entry.linenos for entry in blame_output])
-        assert ranges == flatten([range(2, 3), range(14, 15), range(1, 2), range(3, 14), range(15, 17)]), str(ranges)
+        self.assertEqual(ranges, flatten([range(2, 3), range(14, 15), range(1, 2), range(3, 14), range(15, 17)]))
 
         commits = [entry.commit.hexsha[:7] for entry in blame_output]
-        assert commits == ['82b8902', '82b8902', 'c76852d', 'c76852d', 'c76852d'], str(commits)
+        self.assertEqual(commits, ['82b8902', '82b8902', 'c76852d', 'c76852d', 'c76852d'])
 
         # Original filenames
-        assert all([entry.orig_path == u'AUTHORS' for entry in blame_output])
+        self.assertSequenceEqual([entry.orig_path for entry in blame_output], [u'AUTHORS'] * len(blame_output))
 
         # Original line numbers
         orig_ranges = flatten([entry.orig_linenos for entry in blame_output])
-        assert orig_ranges == flatten([range(2, 3), range(14, 15), range(1, 2), range(2, 13), range(13, 15)]), str(orig_ranges)  # noqa
+        self.assertEqual(orig_ranges, flatten([range(2, 3), range(14, 15), range(1, 2), range(2, 13), range(13, 15)]))   # noqa E501
 
     @patch.object(Git, '_call_process')
     def test_blame_complex_revision(self, git):
         git.return_value = fixture('blame_complex_revision')
         res = self.rorepo.blame("HEAD~10..HEAD", "README.md")
-        assert len(res) == 1
-        assert len(res[0][1]) == 83, "Unexpected amount of parsed blame lines"
+        self.assertEqual(len(res), 1)
+        self.assertEqual(len(res[0][1]), 83, "Unexpected amount of parsed blame lines")
 
     @with_rw_repo('HEAD', bare=False)
     def test_untracked_files(self, rwrepo):
-        for (run, repo_add) in enumerate((rwrepo.index.add, rwrepo.git.add)):
+        for run, (repo_add, is_invoking_git) in enumerate((
+                (rwrepo.index.add, False),
+                (rwrepo.git.add, True),
+        )):
             base = rwrepo.working_tree_dir
             files = (join_path_native(base, u"%i_test _myfile" % run),
                      join_path_native(base, "%i_test_other_file" % run),
@@ -395,9 +424,8 @@ class TestRepo(TestBase):
 
             num_recently_untracked = 0
             for fpath in files:
-                fd = open(fpath, "wb")
-                fd.close()
-            # END for each filename
+                with open(fpath, "wb"):
+                    pass
             untracked_files = rwrepo.untracked_files
             num_recently_untracked = len(untracked_files)
 
@@ -405,10 +433,15 @@ class TestRepo(TestBase):
             num_test_untracked = 0
             for utfile in untracked_files:
                 num_test_untracked += join_path_native(base, utfile) in files
-            assert len(files) == num_test_untracked
+            self.assertEqual(len(files), num_test_untracked)
 
+            if is_win and not PY3 and is_invoking_git:
+                ## On Windows, shell needed when passing unicode cmd-args.
+                #
+                repo_add = fnt.partial(repo_add, shell=True)
+                untracked_files = [win_encode(f) for f in untracked_files]
             repo_add(untracked_files)
-            assert len(rwrepo.untracked_files) == (num_recently_untracked - len(files))
+            self.assertEqual(len(rwrepo.untracked_files), (num_recently_untracked - len(files)))
         # end for each run
 
     def test_config_reader(self):
@@ -420,19 +453,16 @@ class TestRepo(TestBase):
     def test_config_writer(self):
         for config_level in self.rorepo.config_level:
             try:
-                writer = self.rorepo.config_writer(config_level)
-                assert not writer.read_only
-                writer.release()
+                with self.rorepo.config_writer(config_level) as writer:
+                    self.assertFalse(writer.read_only)
             except IOError:
                 # its okay not to get a writer for some configuration files if we
                 # have no permissions
                 pass
-        # END for each config level
 
     def test_config_level_paths(self):
         for config_level in self.rorepo.config_level:
             assert self.rorepo._get_config_path(config_level)
-        # end for each config level
 
     def test_creation_deletion(self):
         # just a very quick test to assure it generally works. There are
@@ -442,15 +472,16 @@ class TestRepo(TestBase):
 
         tag = self.rorepo.create_tag("new_tag", "HEAD~2")
         self.rorepo.delete_tag(tag)
-        writer = self.rorepo.config_writer()
-        writer.release()
+        with self.rorepo.config_writer():
+            pass
         remote = self.rorepo.create_remote("new_remote", "git@server:repo.git")
         self.rorepo.delete_remote(remote)
 
     def test_comparison_and_hash(self):
         # this is only a preliminary test, more testing done in test_index
-        assert self.rorepo == self.rorepo and not (self.rorepo != self.rorepo)
-        assert len(set((self.rorepo, self.rorepo))) == 1
+        self.assertEqual(self.rorepo, self.rorepo)
+        self.assertFalse(self.rorepo != self.rorepo)
+        self.assertEqual(len(set((self.rorepo, self.rorepo))), 1)
 
     @with_rw_directory
     def test_tilde_and_env_vars_in_repo_path(self, rw_dir):
@@ -489,57 +520,59 @@ class TestRepo(TestBase):
         # readlines no limit
         s = mkfull()
         lines = s.readlines()
-        assert len(lines) == 3 and lines[-1].endswith(b'\n')
-        assert s._stream.tell() == len(d)   # must have scrubbed to the end
+        self.assertEqual(len(lines), 3)
+        self.assertTrue(lines[-1].endswith(b'\n'), lines[-1])
+        self.assertEqual(s._stream.tell(), len(d))  # must have scrubbed to the end
 
         # realines line limit
         s = mkfull()
         lines = s.readlines(5)
-        assert len(lines) == 1
+        self.assertEqual(len(lines), 1)
 
         # readlines on tiny sections
         s = mktiny()
         lines = s.readlines()
-        assert len(lines) == 1 and lines[0] == l1p
-        assert s._stream.tell() == ts + 1
+        self.assertEqual(len(lines), 1)
+        self.assertEqual(lines[0], l1p)
+        self.assertEqual(s._stream.tell(), ts + 1)
 
         # readline no limit
         s = mkfull()
-        assert s.readline() == l1
-        assert s.readline() == l2
-        assert s.readline() == l3
-        assert s.readline() == b''
-        assert s._stream.tell() == len(d)
+        self.assertEqual(s.readline(), l1)
+        self.assertEqual(s.readline(), l2)
+        self.assertEqual(s.readline(), l3)
+        self.assertEqual(s.readline(), b'')
+        self.assertEqual(s._stream.tell(), len(d))
 
         # readline limit
         s = mkfull()
-        assert s.readline(5) == l1p
-        assert s.readline() == l1[5:]
+        self.assertEqual(s.readline(5), l1p)
+        self.assertEqual(s.readline(), l1[5:])
 
         # readline on tiny section
         s = mktiny()
-        assert s.readline() == l1p
-        assert s.readline() == b''
-        assert s._stream.tell() == ts + 1
+        self.assertEqual(s.readline(), l1p)
+        self.assertEqual(s.readline(), b'')
+        self.assertEqual(s._stream.tell(), ts + 1)
 
         # read no limit
         s = mkfull()
-        assert s.read() == d[:-1]
-        assert s.read() == b''
-        assert s._stream.tell() == len(d)
+        self.assertEqual(s.read(), d[:-1])
+        self.assertEqual(s.read(), b'')
+        self.assertEqual(s._stream.tell(), len(d))
 
         # read limit
         s = mkfull()
-        assert s.read(5) == l1p
-        assert s.read(6) == l1[5:]
-        assert s._stream.tell() == 5 + 6    # its not yet done
+        self.assertEqual(s.read(5), l1p)
+        self.assertEqual(s.read(6), l1[5:])
+        self.assertEqual(s._stream.tell(), 5 + 6)  # its not yet done
 
         # read tiny
         s = mktiny()
-        assert s.read(2) == l1[:2]
-        assert s._stream.tell() == 2
-        assert s.read() == l1[2:ts]
-        assert s._stream.tell() == ts + 1
+        self.assertEqual(s.read(2), l1[:2])
+        self.assertEqual(s._stream.tell(), 2)
+        self.assertEqual(s.read(), l1[2:ts])
+        self.assertEqual(s._stream.tell(), ts + 1)
 
     def _assert_rev_parse_types(self, name, rev_obj):
         rev_parse = self.rorepo.rev_parse
@@ -549,11 +582,12 @@ class TestRepo(TestBase):
 
         # tree and blob type
         obj = rev_parse(name + '^{tree}')
-        assert obj == rev_obj.tree
+        self.assertEqual(obj, rev_obj.tree)
 
         obj = rev_parse(name + ':CHANGES')
-        assert obj.type == 'blob' and obj.path == 'CHANGES'
-        assert rev_obj.tree['CHANGES'] == obj
+        self.assertEqual(obj.type, 'blob')
+        self.assertEqual(obj.path, 'CHANGES')
+        self.assertEqual(rev_obj.tree['CHANGES'], obj)
 
     def _assert_rev_parse(self, name):
         """tries multiple different rev-parse syntaxes with the given name
@@ -569,7 +603,7 @@ class TestRepo(TestBase):
         # try history
         rev = name + "~"
         obj2 = rev_parse(rev)
-        assert obj2 == obj.parents[0]
+        self.assertEqual(obj2, obj.parents[0])
         self._assert_rev_parse_types(rev, obj2)
 
         # history with number
@@ -582,20 +616,20 @@ class TestRepo(TestBase):
         for pn in range(11):
             rev = name + "~%i" % (pn + 1)
             obj2 = rev_parse(rev)
-            assert obj2 == history[pn]
+            self.assertEqual(obj2, history[pn])
             self._assert_rev_parse_types(rev, obj2)
         # END history check
 
         # parent ( default )
         rev = name + "^"
         obj2 = rev_parse(rev)
-        assert obj2 == obj.parents[0]
+        self.assertEqual(obj2, obj.parents[0])
         self._assert_rev_parse_types(rev, obj2)
 
         # parent with number
         for pn, parent in enumerate(obj.parents):
             rev = name + "^%i" % (pn + 1)
-            assert rev_parse(rev) == parent
+            self.assertEqual(rev_parse(rev), parent)
             self._assert_rev_parse_types(rev, parent)
         # END for each parent
 
@@ -611,7 +645,7 @@ class TestRepo(TestBase):
         rev_parse = self.rorepo.rev_parse
 
         # try special case: This one failed at some point, make sure its fixed
-        assert rev_parse("33ebe").hexsha == "33ebe7acec14b25c5f84f35a664803fcab2f7781"
+        self.assertEqual(rev_parse("33ebe").hexsha, "33ebe7acec14b25c5f84f35a664803fcab2f7781")
 
         # start from reference
         num_resolved = 0
@@ -622,7 +656,7 @@ class TestRepo(TestBase):
                 path_section = '/'.join(path_tokens[-(pt + 1):])
                 try:
                     obj = self._assert_rev_parse(path_section)
-                    assert obj.type == ref.object.type
+                    self.assertEqual(obj.type, ref.object.type)
                     num_resolved += 1
                 except (BadName, BadObject):
                     print("failed on %s" % path_section)
@@ -637,31 +671,31 @@ class TestRepo(TestBase):
 
         # it works with tags !
         tag = self._assert_rev_parse('0.1.4')
-        assert tag.type == 'tag'
+        self.assertEqual(tag.type, 'tag')
 
         # try full sha directly ( including type conversion )
-        assert tag.object == rev_parse(tag.object.hexsha)
+        self.assertEqual(tag.object, rev_parse(tag.object.hexsha))
         self._assert_rev_parse_types(tag.object.hexsha, tag.object)
 
         # multiple tree types result in the same tree: HEAD^{tree}^{tree}:CHANGES
         rev = '0.1.4^{tree}^{tree}'
-        assert rev_parse(rev) == tag.object.tree
-        assert rev_parse(rev + ':CHANGES') == tag.object.tree['CHANGES']
+        self.assertEqual(rev_parse(rev), tag.object.tree)
+        self.assertEqual(rev_parse(rev + ':CHANGES'), tag.object.tree['CHANGES'])
 
         # try to get parents from first revision - it should fail as no such revision
         # exists
         first_rev = "33ebe7acec14b25c5f84f35a664803fcab2f7781"
         commit = rev_parse(first_rev)
-        assert len(commit.parents) == 0
-        assert commit.hexsha == first_rev
+        self.assertEqual(len(commit.parents), 0)
+        self.assertEqual(commit.hexsha, first_rev)
         self.failUnlessRaises(BadName, rev_parse, first_rev + "~")
         self.failUnlessRaises(BadName, rev_parse, first_rev + "^")
 
         # short SHA1
         commit2 = rev_parse(first_rev[:20])
-        assert commit2 == commit
+        self.assertEqual(commit2, commit)
         commit2 = rev_parse(first_rev[:5])
-        assert commit2 == commit
+        self.assertEqual(commit2, commit)
 
         # todo: dereference tag into a blob 0.1.7^{blob} - quite a special one
         # needs a tag which points to a blob
@@ -669,13 +703,13 @@ class TestRepo(TestBase):
         # ref^0 returns commit being pointed to, same with ref~0, and ^{}
         tag = rev_parse('0.1.4')
         for token in (('~0', '^0', '^{}')):
-            assert tag.object == rev_parse('0.1.4%s' % token)
+            self.assertEqual(tag.object, rev_parse('0.1.4%s' % token))
         # END handle multiple tokens
 
         # try partial parsing
         max_items = 40
         for i, binsha in enumerate(self.rorepo.odb.sha_iter()):
-            assert rev_parse(bin_to_hex(binsha)[:8 - (i % 2)].decode('ascii')).binsha == binsha
+            self.assertEqual(rev_parse(bin_to_hex(binsha)[:8 - (i % 2)].decode('ascii')).binsha, binsha)
             if i > max_items:
                 # this is rather slow currently, as rev_parse returns an object
                 # which requires accessing packs, it has some additional overhead
@@ -696,13 +730,13 @@ class TestRepo(TestBase):
         self.failUnlessRaises(BadObject, rev_parse, "%s@{0}" % head.commit.hexsha)
 
         # uses HEAD.ref by default
-        assert rev_parse('@{0}') == head.commit
+        self.assertEqual(rev_parse('@{0}'), head.commit)
         if not head.is_detached:
             refspec = '%s@{0}' % head.ref.name
-            assert rev_parse(refspec) == head.ref.commit
+            self.assertEqual(rev_parse(refspec), head.ref.commit)
             # all additional specs work as well
-            assert rev_parse(refspec + "^{tree}") == head.commit.tree
-            assert rev_parse(refspec + ":CHANGES").type == 'blob'
+            self.assertEqual(rev_parse(refspec + "^{tree}"), head.commit.tree)
+            self.assertEqual(rev_parse(refspec + ":CHANGES").type, 'blob')
         # END operate on non-detached head
 
         # position doesn't exist
@@ -718,13 +752,13 @@ class TestRepo(TestBase):
         target_type = GitCmdObjectDB
         if sys.version_info[:2] < (2, 5):
             target_type = GitCmdObjectDB
-        assert isinstance(self.rorepo.odb, target_type)
+        self.assertIsInstance(self.rorepo.odb, target_type)
 
     def test_submodules(self):
-        assert len(self.rorepo.submodules) == 1     # non-recursive
-        assert len(list(self.rorepo.iter_submodules())) >= 2
+        self.assertEqual(len(self.rorepo.submodules), 1)  # non-recursive
+        self.assertGreaterEqual(len(list(self.rorepo.iter_submodules())), 2)
 
-        assert isinstance(self.rorepo.submodule("gitdb"), Submodule)
+        self.assertIsInstance(self.rorepo.submodule("gitdb"), Submodule)
         self.failUnlessRaises(ValueError, self.rorepo.submodule, "doesn't exist")
 
     @with_rw_repo('HEAD', bare=False)
@@ -737,7 +771,7 @@ class TestRepo(TestBase):
         # test create submodule
         sm = rwrepo.submodules[0]
         sm = rwrepo.create_submodule("my_new_sub", "some_path", join_path_native(self.rorepo.working_tree_dir, sm.path))
-        assert isinstance(sm, Submodule)
+        self.assertIsInstance(sm, Submodule)
 
         # note: the rest of this functionality is tested in test_submodule
 
@@ -747,16 +781,18 @@ class TestRepo(TestBase):
         real_path_abs = os.path.abspath(join_path_native(rwrepo.working_tree_dir, '.real'))
         os.rename(rwrepo.git_dir, real_path_abs)
         git_file_path = join_path_native(rwrepo.working_tree_dir, '.git')
-        open(git_file_path, 'wb').write(fixture('git_file'))
+        with open(git_file_path, 'wb') as fp:
+            fp.write(fixture('git_file'))
 
         # Create a repo and make sure it's pointing to the relocated .git directory.
         git_file_repo = Repo(rwrepo.working_tree_dir)
-        assert os.path.abspath(git_file_repo.git_dir) == real_path_abs
+        self.assertEqual(os.path.abspath(git_file_repo.git_dir), real_path_abs)
 
         # Test using an absolute gitdir path in the .git file.
-        open(git_file_path, 'wb').write(('gitdir: %s\n' % real_path_abs).encode('ascii'))
+        with open(git_file_path, 'wb') as fp:
+            fp.write(('gitdir: %s\n' % real_path_abs).encode('ascii'))
         git_file_repo = Repo(rwrepo.working_tree_dir)
-        assert os.path.abspath(git_file_repo.git_dir) == real_path_abs
+        self.assertEqual(os.path.abspath(git_file_repo.git_dir), real_path_abs)
 
     def test_file_handle_leaks(self):
         def last_commit(repo, rev, path):
@@ -777,7 +813,7 @@ class TestRepo(TestBase):
 
     def test_remote_method(self):
         self.failUnlessRaises(ValueError, self.rorepo.remote, 'foo-blue')
-        assert isinstance(self.rorepo.remote(name='origin'), Remote)
+        self.assertIsInstance(self.rorepo.remote(name='origin'), Remote)
 
     @with_rw_directory
     def test_empty_repo(self, rw_dir):
@@ -785,7 +821,7 @@ class TestRepo(TestBase):
         r = Repo.init(rw_dir, mkdir=False)
         # It's ok not to be able to iterate a commit, as there is none
         self.failUnlessRaises(ValueError, r.iter_commits)
-        assert r.active_branch.name == 'master'
+        self.assertEqual(r.active_branch.name, 'master')
         assert not r.active_branch.is_valid(), "Branch is yet to be born"
 
         # actually, when trying to create a new branch without a commit, git itself fails
@@ -825,12 +861,15 @@ class TestRepo(TestBase):
 
         # two commit merge-base
         res = repo.merge_base(c1, c2)
-        assert isinstance(res, list) and len(res) == 1 and isinstance(res[0], Commit)
-        assert res[0].hexsha.startswith('3936084')
+        self.assertIsInstance(res, list)
+        self.assertEqual(len(res), 1)
+        self.assertIsInstance(res[0], Commit)
+        self.assertTrue(res[0].hexsha.startswith('3936084'))
 
         for kw in ('a', 'all'):
             res = repo.merge_base(c1, c2, c3, **{kw: True})
-            assert isinstance(res, list) and len(res) == 1
+            self.assertIsInstance(res, list)
+            self.assertEqual(len(res), 1)
         # end for each keyword signalling all merge-bases to be returned
 
         # Test for no merge base - can't do as we have
diff --git a/git/test/test_submodule.py b/git/test/test_submodule.py
index 17ce605a..8e2829b2 100644
--- a/git/test/test_submodule.py
+++ b/git/test/test_submodule.py
@@ -9,7 +9,7 @@ from git.test.lib import (
     TestBase,
     with_rw_repo
 )
-from gitdb.test.lib import with_rw_directory
+from git.test.lib import with_rw_directory
 from git.exc import (
     InvalidGitRepositoryError,
     RepositoryDirtyError
@@ -17,7 +17,7 @@ from git.exc import (
 from git.objects.submodule.base import Submodule
 from git.objects.submodule.root import RootModule, RootUpdateProgress
 from git.util import to_native_path_linux, join_path_native
-from git.compat import string_types
+from git.compat import string_types, is_win
 from git.repo.fun import (
     find_git_dir,
     touch
@@ -26,7 +26,7 @@ from git.repo.fun import (
 # Change the configuration if possible to prevent the underlying memory manager
 # to keep file handles open. On windows we get problems as they are not properly
 # closed due to mmap bugs on windows (as it appears)
-if sys.platform == 'win32':
+if is_win:
     try:
         import smmap.util
         smmap.util.MapRegion._test_read_into_memory = True
@@ -49,6 +49,10 @@ prog = TestRootProgress()
 
 class TestSubmodule(TestBase):
 
+    def tearDown(self):
+        import gc
+        gc.collect()
+
     k_subm_current = "c15a6e1923a14bc760851913858a3942a4193cdb"
     k_subm_changed = "394ed7006ee5dc8bddfd132b64001d5dfc0ffdd3"
     k_no_subm_tag = "0.1.6"
@@ -305,7 +309,8 @@ class TestSubmodule(TestBase):
 
             # but ... we have untracked files in the child submodule
             fn = join_path_native(csm.module().working_tree_dir, "newfile")
-            open(fn, 'w').write("hi")
+            with open(fn, 'w') as fd:
+                fd.write("hi")
             self.failUnlessRaises(InvalidGitRepositoryError, sm.remove)
 
             # forcibly delete the child repository
diff --git a/git/test/test_util.py b/git/test/test_util.py
index c6ca6920..36fb5be3 100644
--- a/git/test/test_util.py
+++ b/git/test/test_util.py
@@ -24,7 +24,7 @@ from git.objects.util import (
     parse_date,
 )
 from git.cmd import dashify
-from git.compat import string_types
+from git.compat import string_types, is_win
 
 import time
 
@@ -90,7 +90,11 @@ class TestUtils(TestBase):
         wait_lock = BlockingLockFile(my_file, 0.05, wait_time)
         self.failUnlessRaises(IOError, wait_lock._obtain_lock)
         elapsed = time.time() - start
-        assert elapsed <= wait_time + 0.02  # some extra time it may cost
+        extra_time = 0.02
+        if is_win:
+            # for Appveyor
+            extra_time *= 6  # NOTE: Indeterministic failures here...
+        self.assertLess(elapsed, wait_time + extra_time)
 
     def test_user_id(self):
         assert '@' in get_user_id()
diff --git a/git/util.py b/git/util.py
index f5c69231..814cd7f4 100644
--- a/git/util.py
+++ b/git/util.py
@@ -3,30 +3,18 @@
 #
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
+from __future__ import unicode_literals
 
+import getpass
+import logging
 import os
+import platform
 import re
-import sys
-import time
-import stat
 import shutil
-import platform
-import getpass
-import threading
-import logging
-
-# NOTE:  Some of the unused imports might be used/imported by others.
-# Handle once test-cases are back up and running.
-from .exc import InvalidGitRepositoryError
-
-from .compat import (
-    MAXSIZE,
-    defenc,
-    PY3
-)
+import stat
+import time
 
-# Most of these are unused here, but are for use by git-python modules so these
-# don't see gitdb all the time. Flake of course doesn't like it.
+from git.compat import is_win
 from gitdb.util import (  # NOQA
     make_sha,
     LockedFD,
@@ -36,10 +24,24 @@ from gitdb.util import (  # NOQA
     to_bin_sha
 )
 
+import os.path as osp
+
+from .compat import (
+    MAXSIZE,
+    defenc,
+    PY3
+)
+from .exc import InvalidGitRepositoryError
+
+
+# NOTE:  Some of the unused imports might be used/imported by others.
+# Handle once test-cases are back up and running.
+# Most of these are unused here, but are for use by git-python modules so these
+# don't see gitdb all the time. Flake of course doesn't like it.
 __all__ = ("stream_copy", "join_path", "to_native_path_windows", "to_native_path_linux",
            "join_path_native", "Stats", "IndexFileSHA1Writer", "Iterable", "IterableList",
            "BlockingLockFile", "LockFile", 'Actor', 'get_user_id', 'assure_directory_exists',
-           'RemoteProgress', 'CallableRemoteProgress', 'rmtree', 'WaitGroup', 'unbare_repo')
+           'RemoteProgress', 'CallableRemoteProgress', 'rmtree', 'unbare_repo')
 
 #{ Utility Methods
 
@@ -63,17 +65,23 @@ def rmtree(path):
 
     :note: we use shutil rmtree but adjust its behaviour to see whether files that
         couldn't be deleted are read-only. Windows will not remove them in that case"""
+
     def onerror(func, path, exc_info):
-        if not os.access(path, os.W_OK):
-            # Is the error an access error ?
-            os.chmod(path, stat.S_IWUSR)
-            func(path)
-        else:
-            raise
-    # END end onerror
+        # Is the error an access error ?
+        os.chmod(path, stat.S_IWUSR)
+        func(path)  # Will scream if still not possible to delete.
+
     return shutil.rmtree(path, False, onerror)
 
 
+def rmfile(path):
+    """Ensure file deleted also on *Windows* where read-only files need special treatment."""
+    if osp.isfile(path):
+        if is_win:
+            os.chmod(path, 0o777)
+        os.remove(path)
+
+
 def stream_copy(source, destination, chunk_size=512 * 1024):
     """Copy all data from the source stream into the destination stream in chunks
     of size chunk_size
@@ -107,7 +115,7 @@ def join_path(a, *p):
     return path
 
 
-if sys.platform.startswith('win'):
+if is_win:
     def to_native_path_windows(path):
         return path.replace('/', '\\')
 
@@ -152,6 +160,7 @@ def get_user_id():
 
 def finalize_process(proc, **kwargs):
     """Wait for the process (clone, fetch, pull or push) and handle its errors accordingly"""
+    ## TODO: No close proc-streams??
     proc.wait(**kwargs)
 
 #} END utilities
@@ -324,12 +333,12 @@ class RemoteProgress(object):
 
         You may read the contents of the current line in self._cur_line"""
         pass
-        
+
 
 class CallableRemoteProgress(RemoteProgress):
     """An implementation forwarding updates to any callable"""
     __slots__ = ('_callable')
-    
+
     def __init__(self, fn):
         self._callable = fn
         super(CallableRemoteProgress, self).__init__()
@@ -565,7 +574,10 @@ class LockFile(object):
                           (self._file_path, lock_file))
 
         try:
-            fd = os.open(lock_file, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0)
+            flags = os.O_WRONLY | os.O_CREAT | os.O_EXCL
+            if is_win:
+                flags |= os.O_SHORT_LIVED
+            fd = os.open(lock_file, flags, 0)
             os.close(fd)
         except OSError as e:
             raise IOError(str(e))
@@ -586,12 +598,7 @@ class LockFile(object):
         # instead of failing, to make it more usable.
         lfp = self._lock_file_path()
         try:
-            # on bloody windows, the file needs write permissions to be removable.
-            # Why ...
-            if os.name == 'nt':
-                os.chmod(lfp, 0o777)
-            # END handle win32
-            os.remove(lfp)
+            rmfile(lfp)
         except OSError:
             pass
         self._owns_lock = False
@@ -754,35 +761,6 @@ class Iterable(object):
 #} END classes
 
 
-class WaitGroup(object):
-    """WaitGroup is like Go sync.WaitGroup.
-
-    Without all the useful corner cases.
-    By Peter Teichman, taken from https://gist.github.com/pteichman/84b92ae7cef0ab98f5a8
-    """
-    def __init__(self):
-        self.count = 0
-        self.cv = threading.Condition()
-
-    def add(self, n):
-        self.cv.acquire()
-        self.count += n
-        self.cv.release()
-
-    def done(self):
-        self.cv.acquire()
-        self.count -= 1
-        if self.count == 0:
-            self.cv.notify_all()
-        self.cv.release()
-
-    def wait(self, stderr=b''):
-        self.cv.acquire()
-        while self.count > 0:
-            self.cv.wait()
-        self.cv.release()
-
-
 class NullHandler(logging.Handler):
     def emit(self, record):
         pass
diff --git a/requirements.txt b/requirements.txt
index 2316b96e..85d25511 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,3 @@
 gitdb>=0.6.4
+ddt
+mock
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 35b11153..c7dd25fc 100755
--- a/setup.py
+++ b/setup.py
@@ -15,9 +15,8 @@ import os
 import sys
 from os import path
 
-v = open(path.join(path.dirname(__file__), 'VERSION'))
-VERSION = v.readline().strip()
-v.close()
+with open(path.join(path.dirname(__file__), 'VERSION')) as v:
+    VERSION = v.readline().strip()
 
 with open('requirements.txt') as reqs_file:
     requirements = reqs_file.read().splitlines()
@@ -50,22 +49,18 @@ class sdist(_sdist):
 def _stamp_version(filename):
     found, out = False, list()
     try:
-        f = open(filename, 'r')
+        with open(filename, 'r') as f:
+            for line in f:
+                if '__version__ =' in line:
+                    line = line.replace("'git'", "'%s'" % VERSION)
+                    found = True
+                out.append(line)
     except (IOError, OSError):
         print("Couldn't find file %s to stamp version" % filename, file=sys.stderr)
-        return
-    # END handle error, usually happens during binary builds
-    for line in f:
-        if '__version__ =' in line:
-            line = line.replace("'git'", "'%s'" % VERSION)
-            found = True
-        out.append(line)
-    f.close()
 
     if found:
-        f = open(filename, 'w')
-        f.writelines(out)
-        f.close()
+        with open(filename, 'w') as f:
+            f.writelines(out)
     else:
         print("WARNING: Couldn't find version line in file %s" % filename, file=sys.stderr)
 
@@ -73,6 +68,9 @@ install_requires = ['gitdb >= 0.6.4']
 extras_require = {
     ':python_version == "2.6"': ['ordereddict'],
 }
+test_requires = ['ddt']
+if sys.version_info[:2] < (2, 7):
+    test_requires.append('mock')
 
 try:
     if 'bdist_wheel' not in sys.argv:
@@ -104,10 +102,9 @@ setup(
     license="BSD License",
     requires=['gitdb (>=0.6.4)'],
     install_requires=install_requires,
-    test_requirements=['mock', 'nose'] + install_requires,
+    test_requirements=test_requires + install_requires,
     zip_safe=False,
-    long_description="""\
-GitPython is a python library used to interact with Git repositories""",
+    long_description="""GitPython is a python library used to interact with Git repositories""",
     classifiers=[
         # Picked from
         #   http://pypi.python.org/pypi?:action=list_classifiers