Bump lean-toolchain on nightly-testing #397

	name: Bump lean-toolchain on nightly-testing

	on:
	schedule:
	- cron: '0 9 * * *'
	# 10AM CET/1AM PT, 2 hours after lean4 starts building the nightly.
	# Mathlib's `nightly-testing` branch is bumped one hour later.

	jobs:
	update-toolchain:
	if: github.repository_owner == 'leanprover-community'
	runs-on: ubuntu-latest

	steps:
	- name: Checkout code
	uses: actions/checkout@v4
	with:
	ref: nightly-testing # checkout nightly-testing branch
	token: ${{ secrets.NIGHTLY_TESTING }}

	- name: Get latest release tag from leanprover/lean4-nightly
	id: get-latest-release
	run: \|
	RELEASE_TAG=$(curl -s "https://api.github.com/repos/leanprover/lean4-nightly/releases" \| jq -r '.[0].tag_name')
	echo "RELEASE_TAG=$RELEASE_TAG" >> $GITHUB_ENV

	- name: Update lean-toolchain file
	run: \|
	echo "leanprover/lean4:${RELEASE_TAG}" > lean-toolchain

	- name: Commit and push changes
	run: \|
	git config user.name "leanprover-community-mathlib4-bot"
	git config user.email "[email protected]"
	git add lean-toolchain
	git commit -m "chore: bump to ${RELEASE_TAG}"
	git push origin nightly-testing

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