I have my alpine build image! ingwiephoenix/openadk-abuild:musl-latest

All that's left is for some alpine maintainer to tell me whats missing in the docs so I can bootstrap a repo and start building myself stupid untill I have 3.19. This image has all that one would need to start building - it even launches straight into the abuild home directory with passwordless sudo (because let's be real, this container will spin up and down so many times, setting a password would be a chore in itself) and many tools, including lua and luarocks because abuild itself already needed that.

I will start putting these things on github asap. =)