magit-stash-create: Cannot save the current index state

Question

I'm using magit 20160517.838, Emacs 25.0.50.2

I just upgraded magit from 20160320 to 20160517 and when I try to stash I now get this issue;

magit-stash-create: Cannot save the current index state

I can still manually stash on the command line with

git stash

Update

I've put the debug into my init.el file

(setq magit-git-debug t)

Then I restarted emacs and tried stashing again but no debug console is displayed. I get the following error in my *magit-process file.

128 git … commit-tree --no-gpg-sign -m index on master: 917b40b Revert "electric-pair-mode failed with python files." -p HEAD 8e2cbf3020c9c4d509f98a1924f3d43ba0ed4f12
fatal: Not a valid object name --no-gpg-sign

I think I require updating my git as I'm running an old version '1.9.1'

Answer 1

Indeed Magit does require at least Git v1.9.4.

Answer 2

This could also be due to not having configured git properly:

  git config --global user.email "you@example.com"
  git config --global user.name "Your Name"