Since the release of Ubuntu 20.04, I am seeing bug reports of a failure to upgrade the chromium-browser deb package, such as bug #1874837. The preinstallation script for the updated deb installs the snap, and it appears the store is returning 503 error codes:
=> Installing the chromium snap ==> Checking connectivity with the snap store ==> Installing the chromium snap error: cannot install "chromium": cannot query the store for updates: got unexpected HTTP status code 503 via POST to "https://api.snapcraft.io/v2/snaps/refresh"
My stock answer so far has been to try and reinstall, which seems to consistently succeed.
This is not happening all the time, but I’ve gotten enough reports that I think this should be looked into. Are there known availability problems with the store? What can be done to improve/fix this?