GitHub breaks homebrew in GitHub Actions with only 5 days' notice

This means that you are able to run a ton of tools without any explicit setup steps. It also means they have to maintain all that stuff "forever", and the versioning is very inexact. I feel like this issue is a symptom of that choice. Their base images are huge, though I can't find exact numbers right now since there's not actually any official images for it.

Another issue is that if you try to use a self-hosted runner, all of your actions will break because the self-hosted runner is missing all the preinstalled software. This was pretty confusing to me because this seems to go against the "reproducibility" aspects of a CI. There's not even an (official) way to run GitHub actions locally, so you immediately become dependent on the Microsoft-hosted offer. To me it feels like this was maybe even intentional so you have to buy up their expensive compute minutes when running the same things on a bunch of VPSes is much cheaper.

This is all opposed to GitLab, which solved the same issues years earlier. Here you have to chose your images yourself. It's a bit more work to setup an action because of it, but in my opinion it's much more sustainable and has less surprises in the longer term. There's a single simple command to just run an action locally, and you can easily deploy a runner that will work exactly like the hosted version.

They did not follow their own commitment of announcing a breaking change 1 month before roll out nor do they provide a way to opt out or use an older version of their image.

Moreover, their suggested fixes are incomplete or just don't work.