def get_refs(self, gitdir):
         """Returns a dictionary with refs.
+
+        Note that the keys in the returned dictionary are byte strings as
+        read from git.
         """
         args = ["git", "--git-dir=" + gitdir, "for-each-ref", "refs/heads"]
-        lines = check_output(args).strip().split('\n')
+        lines = check_output(args).strip().split('\n'.encode('ascii'))
         refs = {}
         for line in lines:
-            value, name = line.split(' ')
-            name = name.strip('commit\t')
+            value, name = line.split(' '.encode('ascii'))
+            name = name.strip('commit\t'.encode('ascii'))
             refs[name] = value
         return refs
 
             gitdir = self.repo.gitpath
         else:
             gitdir = os.path.abspath(os.path.join(dirname, '.git'))
-        path = os.path.abspath(os.path.join(dirname, 'git.marks'))
+        path = os.path.abspath(os.path.join(dirname, 'testgit.marks'))
 
         if not os.path.exists(dirname):
             os.makedirs(dirname)