Probably, I see. 

> If it does nothing does this mean it'll run this block every time you run `brew update`?

Yes, `if url =~ %r{(https?://|git(?:@|://))github.com[:/](.+)/(.+)(\.git)?}` block always run.

> Even although we don't support non-GitHub taps we still need to be aware that some users use them and handle that case.

I'll modify.