Re: Crash on MSYS2 with GIT_WORK_TREE

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

Hi valtron,

just to set the record straight on a few of my suggestions that turned out
to be incorrect:

On Wed, 8 Mar 2017, Johannes Schindelin wrote:

> On Tue, 7 Mar 2017, valtron wrote:
> 
> > 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.

It was actually the correct thread.

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

I was wrong. The problem here is git.exe: you would have to uncomment the
'#options("debug","!strip")' line in the git/PKGBUILD file in
https://github.com/Alexpux/MSYS2-packages before rebuilding the package
[*1*], and then reinstalling it (which increases the installed size by
94.82MB to 119.63MB due to the unstripped symbols). But then gdb would
find the symbols alright and you'd see that the crash happens in

#1  0x000000010051aecb in setup_explicit_git_dir
    (gitdirenv=gitdirenv@entry=0x1005a00cc <sign_off_header+556> ".git",
     cwd=cwd@entry=0x10055e970 <cwd>, nongit_ok=nongit_ok@entry=0x0) at
    setup.c:669
669             if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */

and worktree indeed was NULL.

Ciao,
Johannes