fix error out if list or run find no matching environments to run #735

	name: Changelog
	on:
	push:
	branches:
	- master
	pull_request:
	# Important that we run on `labeled` and `unlabeled` to pick up `no-changelog` being added/removed
	# DEV: [opened, reopened, synchronize] is the default
	types: [opened, reopened, synchronize, labeled, unlabeled, ready_for_review]
	jobs:
	validate:
	name: Validate changelog
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	# Include all history and tags
	with:
	fetch-depth: 0

	# Ensure a new reno release note was added in this PR.
	# Use `reno new <slug>` to add a new note to `releasenotes/notes`,
	# or add `no-changelog` label if no release note is needed.
	- name: Ensure release note added
	# Only run this on pull requests
	if: github.event_name == 'pull_request'
	run: scripts/check-releasenotes

	- uses: actions/setup-python@v2
	name: Install Python
	with:
	python-version: '3.8'

	- name: Install Dependencies
	run: pip install reno docutils

	- name: Lint changelog notes
	run: reno lint

	- name: Generate changelog
	run: \|
	reno report \| tee CHANGELOG.rst
	rst2html.py CHANGELOG.rst CHANGELOG.html

	- name: Upload CHANGELOG.rst
	uses: actions/upload-artifact@v2
	with:
	name: changelog
	path: \|
	CHANGELOG.rst
	CHANGELOG.html

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