Re: git mergetool indefinite hang on version 2.10+

From: Jeff King <peff@peff.net>
Date: Nov 9, 2016, 23:13 UTC
Message-ID: <20161109231346.poarr3i47ltkiae3@sigill.intra.peff.net>
In-Reply-To: <CAPd9ww_B7gCxvSuuBzH9AbnLsOF1bC_2+mfk0sVfLFF7YHWvNA@mail.gmail.com>

On Wed, Nov 09, 2016 at 02:54:59PM -0800, Mike Dacre wrote:

> I have no idea how to debug this. As of git version 2.10.0 git hangs
> indefinitely when I run `git mergetool`, the result is the same if I
> run `git mergetool --tool-help`.

Mergetool is a shell script. Try setting GIT_TRACE=1 in the environment to see which git programs it's running. Of course it may be hanging in a non-git program, too. Try:

  PATH=$(git --exec-path):$PATH
  sh -x $(which git-mergetool) --tool-help

to get a dump from the shell.

> I am on Arch Linux, with all of my software updated to the latest
> versions as of this morning. git 2.9.3 and lower works perfectly.
> 
> Any ideas?

If it works on v2.9.3 and the bug reproduces, you should be able to use "git bisect" to find the commit that introduces the problem. There weren't a lot of changes to the shell scripts in that time frame, so just as a guess, it may be related to d323c6b64 (i18n: git-sh-setup.sh: mark strings for translation, 2016-06-17), which was the only significant change in that time.

-Peff