Re: Crash on MSYS2 with GIT_WORK_TREE

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi valtron,

On Tue, 7 Mar 2017, valtron wrote:

> Git 1.12.0.

I take it you meant 2.12.0. And you probably also meant to imply that you
are referring to MSYS2's git.exe in /usr/bin/.

> When GIT_WORK_TREE contains a drive-letter and forward-slashes, some git
> commands crash:
> 
> C:\repo>set GIT_WORK_TREE=C:/repo
> C:\repo>git rev-parse HEAD
>      1 [main] git 2332 cygwin_exception::open_stackdumpfile: Dumping
> stack trace to git.exe.stackdump

This suggests that my assumption above is correct: it looks as if you are
executing <MSYS2>\usr\bin\git.exe here.

The proof lies in the pudding, though, and you are the only person who can
do that unless you post the contents of that git.exe.stackdump.

> Stacktrace from GDB (on git-rev-parse) is:
> 
> #0  0x000000018019634d in strcmp (s1=0x600062080 "/c/repo", s2=0x0)
>    at /msys_scripts/msys2-runtime/src/msys2-runtime/newlib/libc/string/strcmp.c:83
> #1  0x00000001005239f1 in ?? ()
> #2  0x0000000100523f36 in ?? ()
> #3  0x000000010046c6fa in ?? ()
> #4  0x0000000100401b6d in ?? ()
> #5  0x0000000100401e4b in ?? ()
> #6  0x0000000100563593 in ?? ()
> #7  0x0000000180047c37 in _cygwin_exit_return ()
>    at /msys_scripts/msys2-runtime/src/msys2-runtime/winsup/cygwin/dcrt0.cc:1031
> #8  0x0000000180045873 in _cygtls::call2 (this=0xffffce00,
> func=0x180046bd0 <dll_crt0_1(void*)>, arg=0x0,
>    buf=buf@entry=0xffffcdf0) at
> /msys_scripts/msys2-runtime/src/msys2-runtime/winsup/cygwin/cygtls.cc:40
> #9  0x0000000180045924 in _cygtls::call (func=<optimized out>,
> arg=<optimized out>)
>    at /msys_scripts/msys2-runtime/src/msys2-runtime/winsup/cygwin/cygtls.cc:27
> #10 0x0000000000000000 in ?? ()
> Backtrace stopped: previous frame inner to this frame (corrupt stack?)

This may be the wrong thread, though. You can find out what other threads
there are with `info threads` and switch by `thread <id>`, the
backtrace(s) of the other thread(s) may be informative.

Please also note that installing the `msys2-runtime-devel` package via
Pacman may be able to get you nicer symbols.

In any case, this problem is squarely within the MSYS2 runtime. It has
nothing to do with Git except for the motivation to set an environment
variable to an absolute path as you outlined.

Having said that, the problem also occurs when using *MSYS2* git.exe (i.e.
/usr/bin/git.exe, not /mingw64/bin/git.exe) in the Git for Windows SDK.

Ciao,
Johannes