Fix exception causes all over the codebase

3 files changed, 6 insertions, 6 deletions

diff --git a/gitdb/__init__.py b/gitdb/__init__.py
index 5f56773..31e4d45 100644
--- a/gitdb/__init__.py
+++ b/gitdb/__init__.py
@@ -18,8 +18,8 @@ def _init_externals():
 
         try:
             __import__(module)
-        except ImportError:
-            raise ImportError("'%s' could not be imported, assure it is located in your PYTHONPATH" % module)
+        except ImportError as e:
+            raise ImportError("'%s' could not be imported, assure it is located in your PYTHONPATH" % module) from e
         # END verify import
     # END handel imports
 
diff --git a/gitdb/db/mem.py b/gitdb/db/mem.py
index 8711334..5b242e4 100644
--- a/gitdb/db/mem.py
+++ b/gitdb/db/mem.py
@@ -74,8 +74,8 @@ class MemoryDB(ObjectDBR, ObjectDBW):
             # rewind stream for the next one to read
             ostream.stream.seek(0)
             return ostream
-        except KeyError:
-            raise BadObject(sha)
+        except KeyError as e:
+            raise BadObject(sha) from e
         # END exception handling
 
     def size(self):
diff --git a/gitdb/util.py b/gitdb/util.py
index d680f97..c4cafec 100644
--- a/gitdb/util.py
+++ b/gitdb/util.py
@@ -326,8 +326,8 @@ class LockedFD(object):
             else:
                 self._fd = fd
             # END handle file descriptor
-        except OSError:
-            raise IOError("Lock at %r could not be obtained" % self._lockfilepath())
+        except OSError as e:
+            raise IOError("Lock at %r could not be obtained" % self._lockfilepath()) from e
         # END handle lock retrieval
 
         # open actual file if required