Some callers expect e.stderr to be filled on exception

TBR=dpranke@chromium.org
BUG=
TEST=


Review URL: http://codereview.chromium.org/7860038

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@100393 0039d316-1c4b-4281-b951-d872f2087c98

scm.py

@@ -89,7 +89,7 @@ class GIT(object):
   @staticmethod
   def Capture(args, **kwargs):
     return subprocess2.check_output(
-        ['git'] + args, stderr=subprocess2.VOID, **kwargs)
+        ['git'] + args, stderr=subprocess2.PIPE, **kwargs)
 
   @staticmethod
   def CaptureStatus(files, upstream_branch=None):