Have you Cmd-C'd your overcommit and lost your changes?
During overcommit
running I have interrupted the process and received following message
Interrupt signal received. Stopping hooks...
⚠ Hook run interrupted by user
then
Unable to restore working tree after pre-commit hooks run:
STDOUT:
STDERR:unable to refresh index
To my horror, all my changes were lost! Fortunately, those were kept in stash, so simple git stash pop
helped :) More info here