Added debug code to keep lines fed into progress handler and the contents of FETCH_HEAD.

This data will be written into the git-repository itself, prefixed with the
number of the operation.

Thus, a test-run with exactly one fetch operation would look like this afterwards:

ls -l .git
total 96
-----> -rw-r--r--   1 byron  staff   141B Jan 16 11:54 000_debug_git-python_FETCH_HEAD <-----
-----> -rw-r--r--   1 byron  staff   180B Jan 16 11:54 000_debug_git-python_stderr     <-----
-rw-r--r--   1 byron  staff   487B Jan 16 11:54 FETCH_HEAD
-rw-r--r--   1 byron  staff    22B Jan 16 11:54 HEAD
-rw-r--r--   1 byron  staff    41B Jan 16 11:54 ORIG_HEAD
drwxr-xr-x   2 byron  staff    68B Jan 16 11:54 branches/
-rw-r--r--   1 byron  staff   560B Jan 16 11:54 config
-rw-r--r--   1 byron  staff    73B Jan 16 11:54 description
drwxr-xr-x  11 byron  staff   374B Jan 16 11:54 hooks/
-rw-r--r--   1 byron  staff    13K Jan 16 11:54 index
drwxr-xr-x   3 byron  staff   102B Jan 16 11:54 info/
drwxr-xr-x   4 byron  staff   136B Jan 16 11:54 logs/
drwxr-xr-x  12 byron  staff   408B Jan 16 11:54 objects/
-rw-r--r--   1 byron  staff   1.2K Jan 16 11:54 packed-refs
drwxr-xr-x   5 byron  staff   170B Jan 16 11:54 refs/

[ci skip]

Author: Byron

git/remote.py

@@ -338,7 +338,7 @@ class Remote(LazyMixin, Iterable):
     NOTE: When querying configuration, the configuration accessor will be cached
     to speed up subsequent accesses."""
 
-    __slots__ = ("repo", "name", "_config_reader")
+    __slots__ = ("repo", "name", "_config_reader", "fetch_no")
     _id_attribute_ = "name"
 
     def __init__(self, repo, name):
@@ -348,6 +348,7 @@ def __init__(self, repo, name):
         :param name: the name of the remote, i.e. 'origin'"""
         self.repo = repo
         self.name = name
+        self.fetch_no = 0
 
         if os.name == 'nt':
             # some oddity: on windows, python 2.5, it for some reason does not realize
@@ -523,7 +524,9 @@ def _get_fetch_info_from_stderr(self, proc, progress):
 
         progress_handler = progress.new_message_handler()
 
+        stderr_fetch = open(join(self.repo.git_dir, '%03i_debug_git-python_stderr' % self.fetch_no), 'wb')
         def my_progress_handler(line):
+            stderr_fetch.write((line + '\n').encode(defenc))
             for pline in progress_handler(line):
                 if line.startswith('fatal:'):
                     raise GitCommandError(("Error when fetching: %s" % line,), 2)
@@ -539,8 +542,12 @@ def my_progress_handler(line):
 
         # We are only interested in stderr here ...
         handle_process_output(proc, None, my_progress_handler, finalize_process)
+        stderr_fetch.close()
 
         # read head information
+        import shutil
+        shutil.copyfile(join(self.repo.git_dir, 'FETCH_HEAD'), join(self.repo.git_dir, '%03i_debug_git-python_FETCH_HEAD' % self.fetch_no))
+        self.fetch_no += 1
         fp = open(join(self.repo.git_dir, 'FETCH_HEAD'), 'rb')
         fetch_head_info = [l.decode(defenc) for l in fp.readlines()]
         fp.close()