git_cache.py: Clobber git repos if the config is corrupt

git_cache.py

 #!/usr/bin/env python
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A git command for managing a local cache of git repositories."""
 
 from __future__ import print_function
 import errno
 import logging
@@ skipping 228 matching lines @@
     env.setdefault('GIT_ASKPASS', 'true')
     env.setdefault('SSH_ASKPASS', 'true')
     self.print('running "git %s" in "%s"' % (' '.join(cmd), cwd))
     gclient_utils.CheckCallAndFilter([self.git_exe] + cmd, **kwargs)
 
   def config(self, cwd=None):
     if cwd is None:
       cwd = self.mirror_path
 
     # Don't run git-gc in a daemon.  Bad things can happen if it gets killed.
-    self.RunGit(['config', 'gc.autodetach', '0'], cwd=cwd)
+    try:
+      self.RunGit(['config', 'gc.autodetach', '0'], cwd=cwd)
+    except subprocess2.CalledProcessError:
+      # Hard error, need to clobber.
+      raise RefsHeadsFailedToFetch

[Paweł Hajdan Jr., 2016/06/06 11:21:52]

It seems hacky to re-use RefsHeadsFailedToFetch exception in this context.

Possible solutions:

a) rename it to something like ClobberNeeded
b) introduce a new one like GCAutodetachFailed and catch it where we catch
RefsHeadsFailedToFetch
c) have a ClobberNeeded exception both RefsHeadsFailedToFetch and
GCAutodetachFailed would inherit from; only catch ClobberNeeded

Also, it seems we should raise RefsHeadsFailedToFetch(), i.e. instantiate the
class.

[Ryan Tseng, 2016/06/07 20:38:02]

Done.

 
     # Don't combine pack files into one big pack file.  It's really slow for
     # repositories, and there's no way to track progress and make sure it's
     # not stuck.
     self.RunGit(['config', 'gc.autopacklimit', '0'], cwd=cwd)
 
     # Allocate more RAM for cache-ing delta chains, for better performance
     # of "Resolving deltas".
     self.RunGit(['config', 'core.deltaBaseCacheLimit',
                  gclient_utils.DefaultDeltaBaseCacheLimit()], cwd=cwd)
@@ skipping 465 matching lines @@
   dispatcher = subcommand.CommandDispatcher(__name__)
   return dispatcher.execute(OptionParser(), argv)
 
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)