subrepo: use subprocess.Popen without the shell As well as simplifying the code, this makes subprocess calls about 25% faster. Tested on a couple linux boxes. python -mtimeit -s'import subprocess' 'subprocess.Popen( "git version", shell=True, stdout=subprocess.PIPE).wait()' python -mtimeit -s'import subprocess' 'subprocess.Popen( ["git","version"], stdout=subprocess.PIPE).wait()'

subrepo: treat git error code 1 as success At least status, commit, merge-base, and diff all return 1 when not failing.

subrepo: gitsubrepo should inherit from abstractsubrepo