I'm seeing repeated macos failures, eg https://github.com/coq/coq/actions/runs/4427719315/jobs/7765744889
==> Fetching atk
==> Downloading https://ghcr.io/v2/homebrew/core/atk/manifests/2.38.0
curl: (22) The requested URL returned error: 503
Error: gtksourceview3: Failed to download resource "atk_bottle_manifest"
Download failed: https://ghcr.io/v2/homebrew/core/atk/manifests/2.38.0
Last updated: Jun 05 2023 at 10:01 UTC