Library dependencies in Homebrew Python 3.9 are relative paths; absolute paths used to be #38

	name: cleanup caches by a branch
	# https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#force-deleting-cache-entries
	# Caches are very large and must be deleted to prioritize main branch's caches.
	on:
	pull_request:
	types:
	- closed

	jobs:
	cleanup:
	runs-on: ubuntu-latest
	steps:
	- name: Check out code
	uses: actions/checkout@v3

	- name: Cleanup
	run: \|
	gh extension install actions/gh-actions-cache

	REPO=${{ github.repository }}
	BRANCH="refs/pull/${{ github.event.pull_request.number }}/merge"

	echo "Fetching list of cache key"
	cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH \| cut -f 1 )

	## Setting this to not fail the workflow while deleting cache keys.
	set +e
	echo "Deleting caches..."
	for cacheKey in $cacheKeysForPR
	do
	gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
	done
	echo "Done"
	env:
	GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

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