post-checkout hook prevents pre-commit hooks from working with unstaged files #1418
Description
Hi there!
Most important thing first: pre-commit is great, it makes managing git hooks trivial and when combined with static analysis hooks, helps our team immeasurably - thanks for all the hard work.
We have pre-commit hooks that run a bunch of checks, and thanks to #1339, a post-checkout hook that does some workspace analysis and prints a few warnings if needed.
Unfortunately this seems to have broken the "stash unstaged changes" behaviour when committing - the stash runs a git checkout to clear the working directory before running the hooks, and that fails because of the post-checkout hook. I'd expect that the working directory to be cleared as normal, commit OK and then the working directory to be restored as it does without the post-checkout hook, as the actual mechanism behind removing the unstaged changes and restoring them is hidden from the user.
Below is a quick test to reproduce it:
#!/usr/bin/env bash
mkdir test
cd test || exit
git init
# Configure a pre-commit and post-checkout hook
cat << EOF > .pre-commit-config.yaml
repos:
- repo: local
hooks:
- id: pre-commit-ok
name: Pre-commit hook that always passes
stages: [commit]
language: system
entry: sh -c 'exit 0'
always_run: true
- repo: local
hooks:
- id: post-checkout-fail
name: Post-checkout hook that fails
stages: [post-checkout]
language: system
entry: sh -c 'exit 1'
always_run: true
EOF
echo "bananas" > great-things.txt
git add .
git commit -m "init"
# Install the hooks
pre-commit install -t pre-commit
pre-commit install -t post-checkout
# Do a checkout - this is expected to print an error from the lint
git checkout -b test
# Change the original file
echo "platanos" >> great-things.txt
# Add another file and stage it
echo "42" > answer.txt
git add answer.txt
# Attempt to commit the new, staged file.
#
# Without the post-checkout hook, this causes the unstaged changes to be
# stashed and the commit works as normal.
echo ""
echo ""
echo " Attempting to commit with unstaged changes"
echo " This will fail when attempting to checkout as part of the commit hook:"
echo ""
echo ""
git commit -m "more info"Unfortunately there seems to be no easy way to skip the post-checkout hook when clearing the unstaged files with git checkout.
Happy to open a PR to help fix this, just unsure what to do - I could swap the git checkout for a git stash save --keep-index --include-untracked but I assume it is using checkout for reason.