Merge branch 'staging'

Merging all the things from the staging branch. They have all
already been reviewed.

17 files changed, 342 insertions, 131 deletions

diff --git a/README b/README
index 9ed92845..36d33a43 100644
--- a/README
+++ b/README
@@ -80,15 +80,44 @@ For chunks, use the following fields:
   `*-commands` fields; only `autotools` is currently known; the commands
   that the build system specifies can be overridden;
   optional
+
+* `pre-configure-commands`: a list of shell commands to run at 
+  the configuration phase of a build, before the list in `configure-commands`;
+  optional
 * `configure-commands`: a list of shell commands to run at the configuraiton
   phase of a build; optional
+* `post-configure-commands`: a list of shell commands to run at 
+  the configuration phase of a build, after the list in `configure-commands`;
+  optional
+
+* `pre-build-commands`: a list of shell commands to run at 
+  the build phase of a build, before the list in `build-commands`;
+  optional
 * `build-commands`: a list of shell commands to run to build (compile) the
   project; optional
+* `post-build-commands`: a list of shell commands to run at 
+  the build phase of a build, after the list in `build-commands`;
+  optional
+
+* `pre-test-commands`: a list of shell commands to run at 
+  the test phase of a build, before the list in `test-commands`;
+  optional
 * `test-commands`: a list of shell commands to run unit tests and other
   non-interactive tests on the built but un-installed project; optional
+* `post-test-commands`: a list of shell commands to run at 
+  the test phase of a build, after the list in `test-commands`;
+  optional
+
+* `pre-install-commands`: a list of shell commands to run at 
+  the install phase of a build, before the list in `install-commands`;
+  optional
 * `install-commands`: a list of shell commands to install the built project;
   the install should go into the directory named in the `DESTDIR` environment
   variable, not the actual system; optional
+* `post-install-commands`: a list of shell commands to run at 
+  the install phase of a build, after the list in `install-commands`;
+  optional
+
 * `max-jobs`: a string to be given to `make` as the argument to the `-j`
   option to specify the maximum number of parallel jobs; the only sensible
   value is `"1"` (including the quotes), to prevent parallel jobs to run
@@ -96,6 +125,7 @@ For chunks, use the following fields:
   since the other phases are often not safe when run in parallel; `morph`
   picks a default value based on the number of CPUs on the host system;
   optional
+
 * `chunks`: a key/value map of lists of regular expressions; 
   the key is the name
   of a binary chunk, the regexps match the pathnames that will be
@@ -332,7 +362,7 @@ uses the strata that were build in stage 2.
 Legalese
 --------
 
-Copyright (C) 2011, 2012  Codethink Limited
+Copyright (C) 2011-2013  Codethink Limited
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
diff --git a/baserock-bootstrap b/baserock-bootstrap
index 315ed0fa..619baeb4 100755
--- a/baserock-bootstrap
+++ b/baserock-bootstrap
@@ -365,6 +365,49 @@ pass3_build_with_morph_in_chroot()
 {
     echo "Building Baserock with morph"
 
+    cat <<'EOF' >"$LFS/usr/bin/linux-user-chroot"
+#!/bin/sh
+
+CHDIR=.
+
+while true; do
+    case "$1" in
+    --help)
+        echo 'See "man linux-user-chroot"'
+        exit 0
+        ;;
+    --version)
+        echo 'Fake'
+        exit 0
+        ;;
+    --mount-bind)
+        # swallow option and arguments
+        shift 3
+        ;;
+    --mount-readonly)
+        shift 2
+        ;;
+    --mount-proc|--unshare-ipc|--unshare-pid)
+        # swallow configure flag
+        shift
+        ;;
+    --chdir)
+        CHDIR="$2"
+        shift 2
+        ;;
+    *)
+        # terminate arg processing
+        ROOTDIR="$1"
+        shift
+        break
+        ;;
+    esac
+done
+
+exec chroot "$ROOTDIR" sh -c 'cd "$1" && shift && exec "$@"' -- "$CHDIR" "$@"
+EOF
+    chmod +x "$LFS/usr/bin/linux-user-chroot"
+
     cat <<EOF > "$LFS/baserock/build_pass3.sh"
 #!/bin/bash
 set -e
diff --git a/morphlib/app.py b/morphlib/app.py
index 21e18e32..87710ee5 100755
--- a/morphlib/app.py
+++ b/morphlib/app.py
@@ -395,8 +395,9 @@ class Morph(cliapp.Application):
                     chatty=True)
 
         # Log the environment.
-        for name in kwargs['env']:
-            logging.debug('environment: %s=%s' % (name, kwargs['env'][name]))
+        prev = getattr(self, 'prev_env', {})
+        morphlib.util.log_dict_diff(kwargs['env'], prev)
+        self.prev_env = kwargs['env']
 
         # run the command line
         return cliapp.Application.runcmd(self, argv, *args, **kwargs)
diff --git a/morphlib/buildcommand.py b/morphlib/buildcommand.py
index f857171e..dfacd760 100644
--- a/morphlib/buildcommand.py
+++ b/morphlib/buildcommand.py
@@ -223,7 +223,7 @@ class BuildCommand(object):
                 if artifact.source.morphology.needs_staging_area:
                     self.install_fillers(staging_area)
                     self.install_chunk_artifacts(staging_area,
-                                                 deps)
+                                                 deps, artifact)
                     morphlib.builder2.ldconfig(self.app.runcmd,
                                                staging_area.tempdir)
 
@@ -359,7 +359,7 @@ class BuildCommand(object):
                                 filename=filename)
                 staging_area.install_artifact(f)
 
-    def install_chunk_artifacts(self, staging_area, artifacts):
+    def install_chunk_artifacts(self, staging_area, artifacts, parent_art):
         '''Install chunk artifacts into staging area.
 
         We only ever care about chunk artifacts as build dependencies,
@@ -373,7 +373,8 @@ class BuildCommand(object):
         for artifact in artifacts:
             if artifact.source.morphology['kind'] != 'chunk':
                 continue
-            self.app.status(msg='Installing chunk %(chunk_name)s',
+            self.app.status(msg='[%(name)s] Installing chunk %(chunk_name)s',
+                            name=parent_art.name,
                             chunk_name=artifact.name)
             handle = self.lac.get(artifact)
             staging_area.install_artifact(handle)
@@ -381,7 +382,8 @@ class BuildCommand(object):
     def build_and_cache(self, staging_area, artifact):
         '''Build an artifact and put it into the local artifact cache.'''
 
-        self.app.status(msg='Starting actual build')
+        self.app.status(msg='Starting actual build: %(name)s',
+                        name=artifact.name)
         setup_mounts = self.app.settings['staging-chroot']
         builder = morphlib.builder2.Builder(
             self.app, staging_area, self.lac, self.rac, self.lrc,
diff --git a/morphlib/builder2.py b/morphlib/builder2.py
index 82a95820..73745d66 100644
--- a/morphlib/builder2.py
+++ b/morphlib/builder2.py
@@ -377,10 +377,20 @@ class ChunkBuilder(BuilderBase):
         relative_destdir = self.staging_area.relative(destdir)
         self.build_env.env['DESTDIR'] = relative_destdir
 
-        steps = [('configure', False),
-                 ('build', True),
-                 ('test', False),
-                 ('install', False)]
+        steps = [
+            ('pre-configure', False),
+            ('configure', False),
+            ('post-configure', False),
+            ('pre-build', True),
+            ('build', True),
+            ('post-build', True),
+            ('pre-test', False),
+            ('test', False),
+            ('post-test', False),
+            ('pre-install', False),
+            ('install', False),
+            ('post-install', False),
+        ]
         for step, in_parallel in steps:
             with self.build_watch(step):
                 key = '%s-commands' % step
diff --git a/morphlib/buildsystem.py b/morphlib/buildsystem.py
index 6287063a..a6645eb2 100644
--- a/morphlib/buildsystem.py
+++ b/morphlib/buildsystem.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2012  Codethink Limited
+# Copyright (C) 2012-2013  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -32,10 +32,18 @@ class BuildSystem(object):
     '''
 
     def __init__(self):
+        self.pre_configure_commands = []
         self.configure_commands = []
+        self.post_configure_commands = []
+        self.pre_build_commands = []
         self.build_commands = []
+        self.post_build_commands = []
+        self.pre_test_commands = []
         self.test_commands = []
+        self.post_test_commands = []
+        self.pre_install_commands = []
         self.install_commands = []
+        self.post_install_commands = []
 
     def __getitem__(self, key):
         key = '_'.join(key.split('-'))
@@ -82,6 +90,7 @@ class DummyBuildSystem(BuildSystem):
     name = 'dummy'
 
     def __init__(self):
+        BuildSystem.__init__(self)
         self.configure_commands = ['echo dummy configure']
         self.build_commands = ['echo dummy build']
         self.test_commands = ['echo dummy test']
@@ -98,6 +107,7 @@ class AutotoolsBuildSystem(BuildSystem):
     name = 'autotools'
 
     def __init__(self):
+        BuildSystem.__init__(self)
         self.configure_commands = [
             'export NOCONFIGURE=1; ' +
             'if [ -e autogen ]; then ./autogen; ' +
@@ -134,6 +144,7 @@ class PythonDistutilsBuildSystem(BuildSystem):
     name = 'python-distutils'
 
     def __init__(self):
+        BuildSystem.__init__(self)
         self.configure_commands = [
         ]
         self.build_commands = [
@@ -160,6 +171,7 @@ class CPANBuildSystem(BuildSystem):
     name = 'cpan'
 
     def __init__(self):
+        BuildSystem.__init__(self)
         self.configure_commands = [
             'perl Makefile.PL INSTALLDIRS=perl '
             'INSTALLARCHLIB="$PREFIX/lib/perl" '
diff --git a/morphlib/exts/virtualbox-ssh.write b/morphlib/exts/virtualbox-ssh.write
index c21dcc57..9b99c7a1 100755
--- a/morphlib/exts/virtualbox-ssh.write
+++ b/morphlib/exts/virtualbox-ssh.write
@@ -26,6 +26,7 @@ accessed over ssh. The machine gets created, but not started.
 import cliapp
 import os
 import re
+import sys
 import time
 import tempfile
 import urlparse
@@ -68,7 +69,7 @@ class VirtualBoxPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
 
         try:
             self.transfer_and_convert_to_vdi(
-                raw_disk, size, ssh_host, vdi_path)
+                raw_disk, ssh_host, vdi_path)
             self.create_virtualbox_guest(ssh_host, vm_name, vdi_path)
         except BaseException:
             sys.stderr.write('Error deploying to VirtualBox')
@@ -93,14 +94,15 @@ class VirtualBoxPlusSshWriteExtension(morphlib.writeexts.WriteExtension):
             raise cliapp.AppException('Cannot parse location %s' % location)
         return x.netloc, m.group('guest'), m.group('path')
 
-    def transfer_and_convert_to_vdi(self, raw_disk, size, ssh_host, vdi_path):
+    def transfer_and_convert_to_vdi(self, raw_disk, ssh_host, vdi_path):
         '''Transfer raw disk image to VirtualBox host, and convert to VDI.'''
 
         self.status(msg='Transfer disk and convert to VDI')
         with open(raw_disk, 'rb') as f:
             cliapp.runcmd(
                 ['ssh', ssh_host, 
-                 'VBoxManage', 'convertfromraw', 'stdin', vdi_path, str(size)],
+                 'VBoxManage', 'convertfromraw', 'stdin', vdi_path,
+                 str(os.path.getsize(raw_disk))],
                 stdin=f)
 
     def create_virtualbox_guest(self, ssh_host, vm_name, vdi_path):
diff --git a/morphlib/git.py b/morphlib/git.py
index fffc05d0..c491991c 100644
--- a/morphlib/git.py
+++ b/morphlib/git.py
@@ -157,17 +157,45 @@ def update_submodules(app, repo_dir):  # pragma: no cover
         app.runcmd(['git', 'submodule', 'update'], cwd=repo_dir)
 
 
+class ConfigNotSetException(cliapp.AppException):
+
+    def __init__(self, missing, defaults):
+        self.missing = missing
+        self.defaults = defaults
+        if len(missing) == 1:
+            self.preamble = ('Git configuration for %s has not been set. '
+                             'Please set it with:' % missing[0])
+        else:
+            self.preamble = ('Git configuration for keys %s and %s '
+                             'have not been set. Please set them with:'
+                             % (', '.join(missing[:-1]), missing[-1]))
+
+    def __str__(self):
+        lines = [self.preamble]
+        lines.extend('git config --global %s \'%s\'' % (k, self.defaults[k])
+                     for k in self.missing)
+        return '\n    '.join(lines)
+
+
+class IdentityNotSetException(ConfigNotSetException):
+
+    preamble = 'Git user info incomplete. Please set your identity, using:'
+
+    def __init__(self, missing):
+        self.defaults = {"user.name": "My Name",
+                         "user.email": "me@example.com"}
+        self.missing = missing
+
+
 def get_user_name(runcmd):
     '''Get user.name configuration setting. Complain if none was found.'''
     if 'GIT_AUTHOR_NAME' in os.environ:
         return os.environ['GIT_AUTHOR_NAME'].strip()
     try:
-        return runcmd(['git', 'config', 'user.name']).strip()
-    except cliapp.AppException:
-        raise cliapp.AppException(
-            'No git user info found. Please set your identity, using: \n'
-            '    git config --global user.name "My Name"\n'
-            '    git config --global user.email "me@example.com"\n')
+        config = check_config_set(runcmd, keys={"user.name": "My Name"})
+        return config['user.name']
+    except ConfigNotSetException, e:
+        raise IdentityNotSetException(e.missing)
 
 
 def get_user_email(runcmd):
@@ -175,29 +203,24 @@ def get_user_email(runcmd):
     if 'GIT_AUTHOR_EMAIL' in os.environ:
         return os.environ['GIT_AUTHOR_EMAIL'].strip()
     try:
-        return runcmd(['git', 'config', 'user.email']).strip()
-    except cliapp.AppException:
-        raise cliapp.AppException(
-            'No git user info found. Please set your identity, using: \n'
-            '    git config --global user.email "My Name"\n'
-            '    git config --global user.email "me@example.com"\n')
+        cfg = check_config_set(runcmd, keys={"user.email": "me@example.com"})
+        return cfg['user.email']
+    except ConfigNotSetException, e:
+        raise IdentityNotSetException(e.missing)
 
-
-def check_config_set(runcmd, keys=("user.name", "user.email"), cwd='.'):
+def check_config_set(runcmd, keys, cwd='.'):
     ''' Check whether the given keys have values in git config. '''
     missing = []
+    found = {}
     for key in keys:
         try:
-            runcmd(['git', 'config', key], cwd=cwd)
+            value = runcmd(['git', 'config', key], cwd=cwd).strip()
+            found[key] = value
         except cliapp.AppException:
             missing.append(key)
     if missing:
-        if len(missing) == 1:
-            emesg = 'Git configuration for %s has not been set' % missing[0]
-        else:
-            emesg = ('Git configuration for keys %s and %s have not been set'
-                     % (', '.join(missing[:-1]), missing[-1]))
-        raise cliapp.AppException(emesg)
+        raise ConfigNotSetException(missing, keys)
+    return found
 
 
 def set_remote(runcmd, gitdir, name, url):
diff --git a/morphlib/morph2.py b/morphlib/morph2.py
index ee58ecdc..3cdf49a9 100644
--- a/morphlib/morph2.py
+++ b/morphlib/morph2.py
@@ -32,10 +32,18 @@ class Morphology(object):
     static_defaults = {
         'chunk': [
             ('description', ''),
+            ('pre-configure-commands', None),
             ('configure-commands', None),
+            ('post-configure-commands', None),
+            ('pre-build-commands', None),
             ('build-commands', None),
+            ('post-build-commands', None),
+            ('pre-test-commands', None),
             ('test-commands', None),
+            ('post-test-commands', None),
+            ('pre-install-commands', None),
             ('install-commands', None),
+            ('post-install-commands', None),
             ('devices', None),
             ('chunks', []),
             ('max-jobs', None),
diff --git a/morphlib/morph2_tests.py b/morphlib/morph2_tests.py
index d2973d5c..49be9c8c 100644
--- a/morphlib/morph2_tests.py
+++ b/morphlib/morph2_tests.py
@@ -37,10 +37,18 @@ class MorphologyTests(unittest.TestCase):
         self.assertEqual(m['name'], 'foo')
         self.assertEqual(m['kind'], 'chunk')
         self.assertEqual(m['build-system'], 'manual')
+        self.assertEqual(m['pre-configure-commands'], None)
         self.assertEqual(m['configure-commands'], None)
+        self.assertEqual(m['post-configure-commands'], None)
+        self.assertEqual(m['pre-build-commands'], None)
         self.assertEqual(m['build-commands'], None)
+        self.assertEqual(m['post-build-commands'], None)
+        self.assertEqual(m['pre-test-commands'], None)
         self.assertEqual(m['test-commands'], None)
+        self.assertEqual(m['post-test-commands'], None)
+        self.assertEqual(m['pre-install-commands'], None)
         self.assertEqual(m['install-commands'], None)
+        self.assertEqual(m['post-install-commands'], None)
         self.assertEqual(m['max-jobs'], None)
         self.assertEqual(m['chunks'], [])
 
@@ -55,10 +63,18 @@ class MorphologyTests(unittest.TestCase):
             self.assertEqual(m['name'], 'foo')
             self.assertEqual(m['kind'], 'chunk')
             self.assertEqual(m['build-system'], 'manual')
+            self.assertEqual(m['pre-configure-commands'], None)
             self.assertEqual(m['configure-commands'], None)
+            self.assertEqual(m['post-configure-commands'], None)
+            self.assertEqual(m['pre-build-commands'], None)
             self.assertEqual(m['build-commands'], None)
+            self.assertEqual(m['post-build-commands'], None)
+            self.assertEqual(m['pre-test-commands'], None)
             self.assertEqual(m['test-commands'], None)
+            self.assertEqual(m['post-test-commands'], None)
+            self.assertEqual(m['pre-install-commands'], None)
             self.assertEqual(m['install-commands'], None)
+            self.assertEqual(m['post-install-commands'], None)
             self.assertEqual(m['max-jobs'], None)
             self.assertEqual(m['chunks'], [])
 
diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index cc221e85..141c3187 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -30,7 +30,7 @@ import uuid
 import morphlib
 
 
-def requires_git_config(*keys):
+def warns_git_config(keys):
     def decorator(func):
         @functools.wraps(func)
         def check_config(self, *args, **kwargs):
@@ -38,13 +38,17 @@ def requires_git_config(*keys):
                 morphlib.git.check_config_set(self.app.runcmd, keys)
             except cliapp.AppException, e:
                 self.app.status(msg="WARNING: %(message)s",
-                                message=e.msg, error=True)
+                                message=str(e), error=True)
             return func(self, *args, **kwargs)
         return check_config
         
     return decorator
 
 
+warns_git_identity = warns_git_config({'user.name': 'My Name',
+                                       'user.email': 'me@example.com'})
+
+
 class BranchAndMergePlugin(cliapp.Plugin):
 
     def __init__(self):
@@ -588,7 +592,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
             self.remove_branch_dir_safe(workspace, branch_name)
             raise
 
-    @requires_git_config('user.name', 'user.email')
+    @warns_git_identity
     def branch(self, args):
         '''Create a new system branch.'''
 
@@ -609,7 +613,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
         workspace = self.deduce_workspace()
         self._create_branch(workspace, new_branch, repo, commit)
 
-    @requires_git_config('user.name', 'user.email')
+    @warns_git_identity
     def checkout(self, args):
         '''Check out an existing system branch.'''
 
@@ -681,7 +685,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
                 branch_dir, spec['repo'], branch, parent_ref=spec['ref'])
         return repo_dir
 
-    @requires_git_config('user.name', 'user.email')
+    @warns_git_identity
     def edit(self, args):
         '''Edit a component in a system branch.'''
 
@@ -1002,7 +1006,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
         self.print_changelog('The following changes were made but have not '
                              'been committed')
 
-    @requires_git_config('user.name', 'user.email')
+    @warns_git_identity
     def tag(self, args):
         if len(args) < 1:
             raise cliapp.AppException('morph tag expects a tag name')
@@ -1502,7 +1506,6 @@ class BranchAndMergePlugin(cliapp.Plugin):
                 self.reset_work_tree_safe(repo_dir)
             raise
 
-    @requires_git_config('user.name', 'user.email')
     def build(self, args):
         '''Build a system from the current system branch'''
 
diff --git a/morphlib/util.py b/morphlib/util.py
index c832a141..b4e06092 100644
--- a/morphlib/util.py
+++ b/morphlib/util.py
@@ -16,6 +16,7 @@
 import re
 
 import morphlib
+import logging
 
 '''Utility functions for morph.'''
 
@@ -170,6 +171,22 @@ def new_repo_caches(app):  # pragma: no cover
     return lrc, rrc
 
 
+def log_dict_diff(cur, pre): # pragma: no cover
+    '''Log the differences between two dicts to debug log'''
+    dictA = cur
+    dictB = pre
+    for key in dictA.keys():
+        if key not in dictB:
+            logging.debug("New environment: %s = %s" % (key, dictA[key]))
+        elif dictA[key] != dictB[key]:
+            logging.debug(
+                "Environment changed: %(key)s = %(valA)s to %(key)s = %(valB)s"
+                % {"key": key, "valA": dictA[key], "valB": dictB[key]})
+    for key in dictB.keys():
+        if key not in dictA:
+            logging.debug("Environment removed:  %s = %s" % (key, dictB[key]))
+
+
 # This acquired from rdiff-backup which is GPLv2+ and a patch from 2011
 # which has not yet been merged, combined with a tad of tidying from us.
 def copyfileobj(inputfp, outputfp, blocksize=1024*1024):  # pragma: no cover
diff --git a/scripts/edit-morph b/scripts/edit-morph
index a4932e75..967bbc13 100755
--- a/scripts/edit-morph
+++ b/scripts/edit-morph
@@ -41,8 +41,7 @@ class EditMorph(cliapp.Application):
         if expected_kind is not None and morphology['kind'] != expected_kind:
             raise morphlib.Error("Expected: a %s morphology" % expected_kind)
 
-        return morphology
-
+        return morphology, text
 
     def cmd_remove_chunk(self, args):
         '''Removes from STRATUM all reference of CHUNK'''
@@ -53,7 +52,8 @@ class EditMorph(cliapp.Application):
 
         file_name = args[0]
         chunk_name = args[1]
-        morphology = self.load_morphology(file_name, expected_kind = 'stratum')
+        morphology, text = self.load_morphology(file_name,
+                                                expected_kind='stratum')
 
         component_count = 0
         build_depends_count = 0
@@ -68,7 +68,7 @@ class EditMorph(cliapp.Application):
         morphology._dict['chunks'] = new_chunks
 
         with morphlib.savefile.SaveFile(file_name, 'w') as f:
-            morphology.write_to_file(f)
+            morphology.update_text(text, f)
 
         self.output.write("Removed: %i chunk(s) and %i build depend(s).\n" %
                           (component_count, build_depends_count))
@@ -80,7 +80,8 @@ class EditMorph(cliapp.Application):
             raise cliapp.AppException("sort expects a morphology file name")
 
         file_name = args[0]
-        morphology = self.load_morphology(file_name, expected_kind='stratum')
+        morphology, text = self.load_morphology(file_name,
+                                                expected_kind='stratum')
 
         for chunk in morphology['chunks']:
             chunk['build-depends'].sort()
@@ -88,7 +89,7 @@ class EditMorph(cliapp.Application):
         morphology._dict['chunks'] = self.sort_chunks(morphology['chunks'])
 
         with morphlib.savefile.SaveFile(file_name, 'w') as f:
-            morphology.write_to_file(f)
+            morphology.update_text(text, f)
 
     def cmd_to_json(self, args):
         """Convert one or more FILES to JSON.
@@ -101,9 +102,7 @@ class EditMorph(cliapp.Application):
 
         for file_name in args:
             try:
-                with open(file_name, 'r') as f:
-                    text = f.read()
-                morphology = morphlib.morph2.Morphology(text)
+                morphology, text = self.load_morphology(file_name)
 
                 if not file_name.endswith('.yaml'):
                     raise morphlib.Error('file name does not end with .yaml')
@@ -124,9 +123,8 @@ class EditMorph(cliapp.Application):
 
         for file_name in args:
             try:
-                with open(file_name, 'r') as f:
-                    text = f.read()
-                morphology = morphlib.morph2.Morphology(text)
+                morphology, text = self.load_morphology(file_name)
+
                 with morphlib.savefile.SaveFile(file_name + '.yaml', 'w') as f:
                     morphology.update_text(text, f, convert_to='yaml')
             except Exception as e:
diff --git a/scripts/find-artifacts b/scripts/find-artifacts
index bd2c02c8..462126fc 100755
--- a/scripts/find-artifacts
+++ b/scripts/find-artifacts
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (C) 2011-2012  Codethink Limited
+# Copyright (C) 2011-2013  Codethink Limited
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -31,86 +31,27 @@ path = os.path.dirname(os.path.dirname(__file__))
 sys.path.append(path)
 import morphlib
 
-# MountableImage yanked from the TrebuchetPlugin and modified slightly
-class MountableImage(object):
-    '''Mountable image (deals with decompression).
-
-    Note, this is a read-only mount in the sense that the decompressed
-    image is not then recompressed after, instead any changes are discarded.
-
-    '''
-    def __init__(self, app, artifact_path):
-        self.app = app
-        self.artifact_path = artifact_path
-
-    def setup(self, path):
-        (tempfd, self.temp_path) = \
-            tempfile.mkstemp(dir=self.app.settings['tempdir'])
-
-        try:
-            with os.fdopen(tempfd, "wb") as outfh:
-                infh = gzip.open(path, "rb")
-                morphlib.util.copyfileobj(infh, outfh)
-                infh.close()
-        except:
-            os.unlink(self.temp_path)
-            raise
-        part = morphlib.fsutils.setup_device_mapping(self.app.runcmd,
-                                                     self.temp_path)
-        mount_point = tempfile.mkdtemp(dir=self.app.settings['tempdir'])
-        morphlib.fsutils.mount(self.app.runcmd, part, mount_point)
-        self.mount_point = mount_point
-        return mount_point
-
-    def cleanup(self, path, mount_point):
-        try:
-            morphlib.fsutils.unmount(self.app.runcmd, mount_point)
-        except:
-            pass
-        try:
-            morphlib.fsutils.undo_device_mapping(self.app.runcmd, path)
-        except:
-            pass
-        try:
-            os.rmdir(mount_point)
-            os.unlink(path)
-        except:
-            pass
-
-    def __enter__(self):
-        return self.setup(self.artifact_path)
-
-    def __exit__(self, exctype, excvalue, exctraceback):
-        self.cleanup(self.temp_path, self.mount_point)
-
-
-class FindArtifacts(cliapp.Application):
-
-    def add_settings(self):
-        self.settings.string(['cachedir'], 'The directory morph writes its '
-                                           'cache to')
-        self.settings.string(['tempdir'], 'A temporary directory to mount the '
-                                          'system image in')
+class FindArtifacts(morphlib.app.Morph):
 
     def process_args(self, args):
         artifacts_dir = os.path.join(self.settings['cachedir'], 'artifacts')
 
         # args[0] is the path to the built image.
-        # Mount the image
-        mount_point = None
-        with MountableImage(self, args[0]) as mount_point:
-            # For each meta file:
-            metadir = os.path.join(mount_point, 'factory-run', 'baserock')
-            metaglob = os.path.join(metadir, '*.meta')
-            for metafile in glob.iglob(metaglob):
-                metafilepath = os.path.join(metadir, metafile)
-                # Read the file as JSON and extract the kind and cache-key
-                with open(metafilepath) as openedmetafile:
-                    metajson = json.load(openedmetafile)
-                cache_key = metajson['cache-key']
-
-                # Grab every file in the artifact cache which matches the
-                # cache-key
+        artifact = args[0]
+
+        def find_artifacts(dirname):
+            metadirs = [
+                os.path.join(dirname, 'factory', 'baserock'),
+                os.path.join(dirname, 'baserock')
+            ]
+            existing_metadirs = [x for x in metadirs if os.path.isdir(x)]
+            if not existing_metadirs:
+                raise NotASystemArtifactError(artifact)
+            metadir = existing_metadirs[0]
+            for basename in glob.glob(os.path.join(metadir, '*.meta')):
+                metafile = os.path.join(metadir, basename)
+                metadata = json.load(open(metafile))
+                cache_key = metadata['cache-key']
                 artifact_glob = os.path.join(artifacts_dir, cache_key) + '*'
                 found_artifacts = glob.glob(artifact_glob)
                 if not found_artifacts:
@@ -120,4 +61,7 @@ class FindArtifacts(cliapp.Application):
                 for cached_file in found_artifacts:
                     self.output.write(cached_file + "\n")
 
+        morphlib.bins.call_in_artifact_directory(
+            self, artifact, find_artifacts)
+
 FindArtifacts().run()
diff --git a/tests.branching/add-then-edit.script b/tests.branching/add-then-edit.script
new file mode 100755
index 00000000..40ee7161
--- /dev/null
+++ b/tests.branching/add-then-edit.script
@@ -0,0 +1,61 @@
+#!/bin/sh
+#
+# Copyright (C) 2013  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+## Test the workflow of adding a new chunk to a stratum then editing it
+
+set -eu
+
+cd "$DATADIR/workspace"
+"$SRCDIR/scripts/test-morph" init
+"$SRCDIR/scripts/test-morph" branch test:morphs "me/add-then-edit"
+
+cd "me/add-then-edit"
+
+# add a chunk
+cd test:morphs
+
+## Sub-optimally, to alter the stratum, you have to `morph edit` it first
+"$SRCDIR/scripts/test-morph" edit hello-system hello-stratum
+
+git apply <<'EOF'
+diff --git a/hello-stratum.morph b/hello-stratum.morph
+index 3b7be17..c79a9af 100644
+--- a/hello-stratum.morph
++++ b/hello-stratum.morph
+@@ -7,6 +7,12 @@
+             "repo": "test:hello",
+             "ref": "master",
+             "build-depends": []
++        },
++        {
++            "name": "goodbye",
++            "repo": "test:goodbye",
++            "ref": "master",
++            "build-depends": []
+         }
+     ]
+ }
+EOF
+
+"$SRCDIR/scripts/test-morph" edit hello-system hello-stratum goodbye
+
+# check whether the stratum still contains the goodbye chunk
+grep -qFe goodbye hello-stratum.morph
+
+# check whether edit has cloned the repository to the right branch
+git --git-dir="../test:goodbye/.git" rev-parse --abbrev-ref HEAD
diff --git a/tests.branching/add-then-edit.setup b/tests.branching/add-then-edit.setup
new file mode 100755
index 00000000..7dbe28c0
--- /dev/null
+++ b/tests.branching/add-then-edit.setup
@@ -0,0 +1,40 @@
+#!/bin/sh
+# Copyright (C) 2013  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+set -eu
+
+# Create goodbye chunk
+mkdir "$DATADIR/goodbye"
+cd "$DATADIR/goodbye"
+
+cat >goodbye <<'EOF'
+#!/bin/sh
+echo goodbye
+EOF
+chmod +x goodbye
+
+cat >goodbye.morph <<'EOF'
+{
+    "name": "goodbye",
+    "kind": "chunk",
+    "install-commands": [
+        "install goodbye \"$DESTDIR$PREFIX/bin/goodbye\""
+    ]
+}
+EOF
+git init .
+git add goodbye.morph goodbye
+git commit -m "Initial commit"
diff --git a/tests.branching/add-then-edit.stdout b/tests.branching/add-then-edit.stdout
new file mode 100644
index 00000000..e0950ab5
--- /dev/null
+++ b/tests.branching/add-then-edit.stdout
@@ -0,0 +1 @@
+me/add-then-edit