Git 2.19.1 crashes while `git gc` in Windows

[guoxiao]

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

I found previous issues like this which was fixed in 2.19.1, but git still crashes on my machine after I upgraded to the latest version.

Setup

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

$ git --version --build-options

git version 2.19.1.windows.1
cpu: x86_64
built from commit: 11a3092e18f2201acd53e45aaa006f1601b6c02a
sizeof-long: 4
sizeof-size_t: 8

• 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 10.0.17134.320]

• 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

Editor Option: VIM
Custom Editor Path:
Path Option: Cmd
SSH Option: OpenSSH
CURL Option: WinSSL
CRLF Option: CRLFCommitAsIs
Bash Terminal Option: MinTTY
Performance Tweaks FSCache: Enabled
Use Credential Manager: Enabled
Enable Symlinks: Enabled
Enable Builtin Rebase: Enabled
Enable Builtin Stash: Enabled

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

I use powershell with poshgit plugin.

Details

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

Powershell

• 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.

git gc

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

It works without error.

• What actually happened instead?

It crashed with message:

Enumerating objects: 952556, done.
error: failed to run repack03/952556)

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

It occurs on a internal repo that I cannot share here. The crash dump file is here:
git.exe.14828.zip

I tried the latest snapshot at https://wingit.blob.core.windows.net/files/index.html but the error still exists.

[orgads]

Happened to me too.

[dscho]

This looks quite similar to #1839 with the notable difference that this here ticket does not provide a Minimal, Complete & Verifiable Example. Could somebody provide one?

[dscho]

@orgads could you please come up with an MCVE? If there is no way to reproduce this reliably, we cannot fix this.

[orgads]

Didn't have this so far with 2.19.2.

[dscho]

843931b was already integrated in v2.19.1. I do not see anything relevant to gc that is different between v2.19.1 and v2.19.2...

And the symptom really looks like the one of the bug fixed in said commit. So I am really at a loss here.

[orgads]

Good point. I have no idea then. If it happens again, I'll try to investigate further.

[dscho]

On Thu, 29 Nov 2018, Orgad Shaneh wrote: Good point. I have no idea then. If it happens again, I'll try to investigate further.

👍 Thank you!

[Neumann-A]

seems the issue is still there:

C:\Sources\Repos\SVN\mpiThirdParty>git --version
git version 2.20.0.windows.1

C:\Sources\Repos\SVN\mpiThirdParty>git gc
Enumerating objects: 49480, done.
fatal: failed to run repack4/49480)

C:\Sources\Repos\SVN\mpiThirdParty>ver

Microsoft Windows [Version 6.1.7601]

If you tell me how to build git by hand using VS Code or Visual Studio (or CMake). I could try debugging it or finding out where exactly it crashes.
figured it out. Just checkout vs/master ;)

[Neumann-A]

Ausnahmefehler bei 0x0000000077122B04 (ntdll.dll) in git.exe: 0xC0000005: Zugriffsverletzung beim Schreiben an Position 0x0000000000000024
(Access violation exception for those who don't speak german)

If I pause git in the debugger i see the following in the main thread:

other thread(s) just seems to wait.

I cannot see anything obviously wrong with it, so i need a little bit more help with debugging it.

[ikmplx]

I can reproduce crash with following steps:

# Initialize repo
git init

# Generate 3.6 GB of pseudorandom data
cat /dev/zero | openssl enc -aes-128-ctr -pass pass:"qwerty" -nosalt | dd bs=1M count=3600 iflag=fullblock of=test

git add test
git repack

gdb stacktrace:

(gdb) run
Starting program: D:\git-sdk-64\usr\src\git\git.exe "--exec-path=D:/git-sdk-64/usr/src/git" pack-objects --delta-base-offset .git/objects/pack/.tmp-13040-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --unpacked --incremental
[New Thread 5004.0x23bc]
[New Thread 5004.0x2838]
[New Thread 5004.0x2124]
[New Thread 5004.0x33b4]
14:48:36.163521 exec-cmd.c:236          trace: resolved executable dir: D:/git-sdk-64/usr/src/git
14:48:36.167013 git.c:418               trace: built-in: git pack-objects --delta-base-offset .git/objects/pack/.tmp-13040-pack --keep-true-parents --honor-pack-keep --non-empty --all --reflog --indexed-objects --unpacked --incremental
[New Thread 5004.0x97c]

Enumerating objects: 1, done.
[Thread 5004.0x97c exited with code 0]
[New Thread 5004.0x16e4]

Thread 1 received signal SIGSEGV, Segmentation fault.
0x00007ffbb371d979 in ntdll!TpSetWait () from C:\WINDOWS\SYSTEM32\ntdll.dll
(gdb)
(gdb) bt
#0  0x00007ffbb371d979 in ntdll!TpSetWait ()
   from C:\WINDOWS\SYSTEM32\ntdll.dll
#1  0x00007ffbb37183e7 in ntdll!RtlEnterCriticalSection ()
   from C:\WINDOWS\SYSTEM32\ntdll.dll
#2  0x00007ffbb3718300 in ntdll!RtlEnterCriticalSection ()
   from C:\WINDOWS\SYSTEM32\ntdll.dll
#3  0x000000000047026c in oe_get_size_slow (pack=0x73fc20 <to_pack>,
    e=0x3684248) at builtin/pack-objects.c:1996
#4  0x000000000046ba17 in oe_set_size (pack=0x73fc20 <to_pack>, e=0x3684248,
    size=3774873600) at ./pack-objects.h:362
#5  0x000000000046f957 in check_object (entry=0x3684248)
    at builtin/pack-objects.c:1655
#6  0x000000000046ff53 in get_object_details () at builtin/pack-objects.c:1873
#7  0x0000000000471c01 in prepare_pack (window=10, depth=50)
    at builtin/pack-objects.c:2615
#8  0x00000000004746f5 in cmd_pack_objects (argc=0, argv=0x3670a08,
    prefix=0x0) at builtin/pack-objects.c:3491
#9  0x0000000000402e3b in run_builtin (p=0x680700 <commands+1728>, argc=11,
    argv=0x3670a08) at git.c:421
#10 0x00000000004031f6 in handle_builtin (argc=11, argv=0x3670a08)
    at git.c:653
#11 0x0000000000403421 in run_argv (argcp=0x136fdc0, argv=0x136fd68)
    at git.c:707
#12 0x000000000040382f in cmd_main (argc=11, argv=0x3670a08) at git.c:829
#13 0x00000000004bfa6f in main (argc=13, argv=0x36709f8) at common-main.c:45

$ git --version --build-options
git version 2.20.0.windows.1
cpu: x86_64
built from commit: 95155834166f64fe9666f2c0a4909f076080893a
sizeof-long: 4
sizeof-size_t: 8

[dscho]

Good news: this looks like it might be fixed by https://public-inbox.org/git/nycvar.QRO.7.76.6.1901181150450.41@tvgsbejvaqbjf.bet/T/#t.