CleanUpCachePostPR #156

	name: CleanUpCachePostPR

	on:
	workflow_run:
	workflows: [PostPR]
	types:
	- completed

	jobs:
	CleanUpCcacheCachePostPR:
	name: Clean Up Ccache Cache Post PR
	runs-on: ubuntu-latest
	permissions:
	actions: write
	contents: read
	env:
	GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
	steps:
	- uses: actions/checkout@v4
	- name: Clean up ccache
	run: \|
	gh extension install actions/gh-actions-cache

	REPO=${{ github.repository }}

	# For debugging cat ${GITHUB_EVENT_PATH} to see the payload.

	pr_head_sha=${{ github.event.workflow_run.head_sha }}
	pr_number=$(gh pr list --state all --search $pr_head_sha --json number --jq '.[0].number')
	echo "Post-PR cache cleanup for PR ${pr_number}"
	BRANCH=refs/pull/${pr_number}/merge

	# Setting this to not fail the workflow while deleting cache keys.
	set +e

	keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH \| cut -f 1)
	# $keys might contain spaces. Thus we set IFS to \n.
	IFS=$'\n'
	for k in $keys
	do
	gh actions-cache delete "$k" -R $REPO -B $BRANCH --confirm
	done
	unset IFS

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