Rework git caches to be bare mirrors of the repos.

This reworks the code for managing and using the git caches in morph to treat
the caches as bare repositories which are mirrors of where we clone from.  In
addition we correctly prune the branches during updates, so that we don't end
up accumulating pointless branches over and over.  This is even more important
with branch-and-merge generating temporary build refs for things.

1 files changed, 4 insertions, 1 deletions

diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index d3aced4b..82d83a58 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -194,7 +194,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
             os.makedirs(parent_dir)
 
         # Clone it from cache to target directory.
-        repo.checkout(ref, os.path.abspath(dirname))
+        repo.clone_checkout(ref, os.path.abspath(dirname))
 
         # Remember the repo name we cloned from in order to be able
         # to identify the repo again later using the same name, even
@@ -221,6 +221,9 @@ class BranchAndMergePlugin(cliapp.Plugin):
             with open(filename) as f:
                 text = f.read()
         else:
+            ref = morphlib.git.find_first_ref(self.app.runcmd, repo_dir, ref)
+            logging.warning("Running git cat-file blob %s:%s.morph in %s" % (
+                    ref, name, repo_dir))
             text = self.app.runcmd(['git', 'cat-file', 'blob',
                                    '%s:%s.morph' % (ref, name)], cwd=repo_dir)
         morphology = morphlib.morph2.Morphology(text)