'git gc' hangs/crashes when working with geany

[ascherer]

• I was not able to find an open or closed issue matching what I'm seeing

Setup

• Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

$ git --version --build-options

git version 2.11.1.windows.1
built from commit: 1c1842bcba45569a84112ec64f72b08eb2d57c68
sizeof-long: 4
machine: x86_64

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

$ cmd.exe /c ver

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. Alle Rechte vorbehalten.

• What options did you set as part of the installation? Or did you choose the
  defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

cat: /etc/install-options.txt: No such file or directory

• Any other interesting things about your environment that might be related
  to the issue you're seeing?

In older versions of Git for Windows, it was possible to abort git gc with Ctrl-C.

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

Bash

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

cd github/debbuild
[Edit some files of this project in Geany 1.29]
git gc

• What did you expect to occur after running these commands?

I expected to see git gc run to completion and compactify .git/objects/.

• What actually happened instead?

git gc hangs. When I quit Geany 1.29, I can Ctrl-C the running git gc. Trying git gc again results in the warning message

$ git gc
fatal: gc is already running on machine 'WKM-W040-80XA' pid 6892 (use --force if not)

• If the problem was occurring with a specific repository, can you provide the
  URL to that repository to help us with testing?

The problem is reproducible with any local repository.

[dscho]

It may be possible that git gc wanted to print an error that some process is blocking some file or directory from being removed. A bug in v2.11.1 would prevent that error from actually be printed (the buggy code waits until more stuff accumulates to be printed, but that does not happen, of course).

Would you mind testing this hypothesis by installing, say, https://github.com/git-for-windows/git/releases/tag/v2.11.1.windows-prerelease.2?

[ascherer]

git version 2.11.1.windows.prerelease.2
built from commit: 86d49ccac7afb39e03ba2632803c5ab67d4bb792
sizeof-long: 4
machine: x86_64

shows the same behavior as before. No error/warning message is printed.

[dscho]

86d49cc

Oh bummer, sorry, I forgot that this version already had the "buffered stderr" bug. I think the version to verify that there is a question hanging is v2.10.2. For testing, I would suggest the portable version: https://github.com/git-for-windows/git/releases/download/v2.10.2.windows.1/PortableGit-2.10.2-64-bit.7z.exe

[ascherer]

git version 2.10.2.windows.1
sizeof-long: 4
machine: x86_64

correctly reports

$ git gc
Counting objects: 557, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (185/185), done.
Writing objects: 100% (557/557), done.
Total 557 (delta 368), reused 557 (delta 368)
Unlink of file '.git/objects/pack/pack-b9c6732d813db7d9882d43795c912415a84936fb.pack' failed. Should I try again? (y/n)

If I quit Geany and answer y, git gc runs to completion. (If I abort with Ctrl-C and rerun, I am requested to use option --force.)

[dscho]

Okay, good. It would appear that the bug fix we already have in master fixes this issue, too, then.

Even if it is not obvious from the descriptions, the same bug is the reason for #1062 and #1064.