My first thought was that this should be configurable, but it might already be.

We have the rawhide_branch option in the config, which defaults to master. It should be possible for fedora-infra to change this configuration.

Ah, ok, I am wrong about that setting. It appears that MBS has a number of hard-coded references to "master", including this bit in format_mmd:

if not pkg.get_ref():
    pkg.set_ref("master")

We also have in submit_module_build_from_yaml()

module_stream = stream or stream_or_packager.get_stream_name() or "master"

And in the SCM class:

self.branch = branch if branch else "master"

At any rate, seems like the thing to do is add a default_branch configuration option that all these bits use instead. I'd say that this option should still default to "master" though, for backwards compatibility.

Okay, that works, but how does setting the rawhide_branch config will affect? Just wondering if its the right thing to do, should I wait until we have all the hard coded bits sorted?

Commit 6cd10004 fixes this issue

This issue has been migrated to Fedora Forge:
https://forge.fedoraproject.org/koji/mbs/issues/1735

Please continue any further discussion there.