Sometimes (or even most of the time) you want your builds to fail as soon as one architecture fails. In fact, this used to be the default for Fedora's koji instance but many years ago that changed and so it is a common sight to see some build which failed hours ago on x86_64 still grinding away on armv7hl.

As of about nine months ago, koji build supports the --fail-fast flag. Could support for this percolate up to fedpkg in some manner? At least fedpkg build and fedpkg scratch-build could use it. I would even argue that --fail-fast should be the default for scratch-build, if not everywhere, but I suppose that would have to be a separate discussion.

I'll see if I can't come up with a PR for at least the most basic of support. Complete support would probably involve adding --fail-fast and --no-fail-fast flags, and a configuration setting to choose the default. (I would certainly want it enabled for every build I do, scratch or otherwise, and it would be a shame to have to use a shell alias or patch locally.) If that is something which might be accepted, I may need some guidance to get it implemented.

I'll see if I can't come up with a PR for at least the most basic of support.