Git GUI crashes every time it opens a repository

Since few days ago, every time I start Git GUI in a repository, it displays this horrifying error message and quits after I click OK: ``` prepare-commit-msg hook failed: 0 [main] us 0 init_cheap: VirtualAlloc pointer is null, Win32 error 487 AllocationBase 0x0, BaseAddress 0x68560000, RegionSize 0x260000, State 0x10000 C:\Program Files (x86)\Git\bin\sh.exe: *** Couldn't reserve space for cygwin's heap, Win32 error 0 You must correct the above errors before committing. ``` It only happens with Git GUI and only when in repository (old or newly created one). Common commands in Git Bash including commit work fine. Un-installing and re-installing with newer package (only minor version change) did not remove the issue. It still happens with old repositories as well as with newly created ones. On a clean machine this issue does not reproduce, so I guess it's something on my box, but I don't remember installing anything funny. I do remember turning off my box after a long time though, so maybe some Windows Update could have triggered this--that would also explain why the other machine does not suffer--it's 2-3 months since last Win update there. Any ideas how to shed light into this? (As I can only see it on single machine, I don't feel like submitting it to official tracker before I know it's not my/other app's fault...) Update after first comments: If you remove or rename the hook script, does it work? Funny enough, but the hook script actually does not exist at all (no hook scripts are present--there are only *.sample files in .git\hooks). Not even elsewhere (git program dir, etc.) Trace it so you know what commands it ran - from git-bash run `git gui --trace` Sadly this does not output anything to the shell. Behaviour is the same. Maybe get gdb in there. I tried but gdb did not output anything useful. However, I don't have any experience with GDB, I'm probably doing it wrong. I got a MinGW's gdb, ran it from command prompt with git.exe as argument and then ran `run gui`. gdb did not output anything interesting: ``` (gdb) run gui Starting program: C:\Program Files (x86)\Git\bin\git.exe gu [New Thread 8264.0x1ce4] [New Thread 8264.0x394] [Inferior 1 (process 8264) exited with code 01] (gdb) ``` But I'm almost sure I'm Doing It Wrong, so advice is more than welcome :) Make sure you don't have cygwin installed or at least that it is not present in your PATH at all I do have cygwin installed (as I always had, before git broke). From Cygwin I only have in path some *.bat launchers and some *.dll files, but I have checked with ProcMon that it does not touch them and even if I remove them from the path I still get the same crash.