Github/Cygwin error: cygheap base mismatch detected

Question

Git has been giving me this error

    0 [main] sh (47116) C:\\Users\\Marcus\\AppData\\Local\\GitHub\\PortableGit_c7e0cbde92ba565cb218a521411d0e854079a28c\\us         


        

Answer 1

I had a very similar problem, but neither restarts nor reinstalling git or cygwin helped. I always got:

      1 [main] sh (12220) C:\Program Files\Git\usr\bin\sh.exe: *** fatal error - cygheap base mismatch detected - 0x37C7408/0x38E7408.
This problem is probably due to using incompatible versions of the cygwin DLL.
Search for cygwin1.dll using the Windows Start->Find/Search facility
and delete all but the most recent version.  The most recent version *should*
reside in x:\cygwin\bin, where 'x' is the drive on which you have
installed the cygwin distribution.  Rebooting is also suggested if you
are unable to find another cygwin DLL.
      0 [main] sh 6928 fork: child -1 - forked process 12220 died unexpectedly, retry 0, exit code 0xC0000142, errno 11
C:\Program Files\Git\mingw64/libexec/git-core\git-stash: fork: retry: Resource temporarily unavailable

Took me a while to figure out that it started after I read about a windows bug related to "System-wide mandatory ASLR", and how the settings available via Windows UI weren't setting the proper registry keys. After making my system more secure by adding this registry entry, cygwin forking broke:

Windows Registry Editor Version 5.00 
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\kernel]
"MitigationOptions"=hex:00,01,01,00,00,00,00,00,00,00,00,00,00,00,00,00

Source: Clarifying the behavior of mandatory ASLR

That resulted in git-stash not working anymore, nor cygwin working (which I installed later. Removing that registry key again fixed the issue.