"git add --patch" aka add --interactive fails with perl error

$ git add --interactive .
C:\Program Files (x86)\Git\bin\perl.exe: *** couldn't commit memory for cygwin heap, Win32 error 0
C:\Program Files (x86)\Git\bin\perl.exe: *** couldn't commit memory for cygwin heap, Win32 error 0
staged unstaged path

• • • Commands ***
      1: status 2: update 3: revert 4: add untracked
      5: patch 6: diff 7: quit 8: help
      What now> 7
      Bye.

$ git add --patch .
C:\Program Files (x86)\Git\bin\perl.exe: *** couldn't commit memory for cygwin heap, Win32 error 0
C:\Program Files (x86)\Git\bin\perl.exe: *** couldn't commit memory for cygwin heap, Win32 error 0
No changes.

$ git status

1. On branch master
2. Changes to be committed:
3. (use "git reset HEAD <file>..." to unstage)
   #
4. modified: .gitignore
   #
5. Changes not staged for commit:
6. (use "git add <file>..." to update what will be committed)
7. (use "git checkout – <file>..." to discard changes in working directory)
   #
8. modified: .gitignore
   #