fix(docs): be clear about exit code handling

When pushing/pulling, we ignore errors unless it's exit code 128.
The reason for this is now made explicit to make clear that issues
are handled by PushInfo flags accordingly.

Related #271

git/test/lib/helper.py

@@ -232,7 +232,13 @@ def remote_repo_creator(self):
             prev_cwd = os.getcwd()
             os.chdir(rw_repo.working_dir)
             try:
-                return func(self, rw_repo, rw_remote_repo)
+                try:
+                    return func(self, rw_repo, rw_remote_repo)
+                except:
+                    print("Keeping repos after failure: repo_dir = %s, remote_repo_dir = %s"
+                          % (repo_dir, remote_repo_dir), file=sys.stderr)
+                    repo_dir = remote_repo_dir = None
+                    raise
             finally:
                 # gd.proc.kill() ... no idea why that doesn't work
                 if gd is not None:
@@ -241,8 +247,10 @@ def remote_repo_creator(self):
                 os.chdir(prev_cwd)
                 rw_repo.git.clear_cache()
                 rw_remote_repo.git.clear_cache()
-                shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
-                shutil.rmtree(remote_repo_dir, onerror=_rmtree_onerror)
+                if repo_dir:
+                    shutil.rmtree(repo_dir, onerror=_rmtree_onerror)
+                if remote_repo_dir:
+                    shutil.rmtree(remote_repo_dir, onerror=_rmtree_onerror)
 
                 if gd is not None:
                     gd.proc.wait()

git/util.py

@@ -159,6 +159,23 @@ def finalize_process(proc):
     except GitCommandError:
         # if a push has rejected items, the command has non-zero return status
         # a return status of 128 indicates a connection error - reraise the previous one
+        # Everything else will still be parsed and made available through PushInfo flags
+        # Estimated error results look like this:
+        # ```bash
+        # To /var/folders/xp/m48gs2tx2vg95tmtzw7tprs40000gn/T/tmpk5jeBeremote_repo_test_base
+        # !   refs/heads/master:refs/heads/master [rejected] (non-fast-forward)
+        # Done
+        # error: failed to push some refs to
+        # '/var/folders/xp/m48gs2tx2vg95tmtzw7tprs40000gn/T/tmpk5jeBeremote_repo_test_base'
+        # hint: Updates were rejected because the tip of your current branch is behind
+        # hint: its remote counterpart. Integrate the remote changes (e.g.
+        # hint: 'git pull ...') before pushing again.
+        # hint: See the 'Note about fast-forwards' in 'git push --help' for details.
+        # ```
+        # See https://github.com/gitpython-developers/GitPython/blob/master/git/test/test_remote.py#L305
+        # on how to check for these kinds of errors.
+        # Also see this issue for a reason for this verbosity:
+        # https://github.com/gitpython-developers/GitPython/issues/271
         if proc.poll() == 128:
             raise
         pass