Add warning to polygon fences #7931

	name: Test wiki Linux

	on: [push, pull_request]
	# paths:
	# - "*"
	# - "!README.md" <-- don't rebuild on doc change
	env:
	TEST: "1"
	jobs:

	build-linux:

	runs-on: ubuntu-22.04
	strategy:
	fail-fast: false # don't cancel if a job from the matrix fails
	matrix:
	python-version: ["3.8", "3.10"]

	steps:
	- uses: actions/checkout@v4
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}
	- name: Setting environment
	run: \|
	mkdir /tmp/web
	./Sphinxsetup.sh
	- name: Check image formats
	run: \|
	find ./images/ -exec file {} + \| grep RIFF -vzq
	- name: Check python3 flake8 formatting
	run : \|
	set -eux -o pipefail
	flake8 .
	- name: Test build
	run: \|
	export AP_SPHINXOPTS=-W
	./update.py --parallel 4 --verbose --destdir=/tmp/web

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