As seen in this issue, if Koji reports a tag error after the build step MBS does not update the build with that information. This should be changed for clarity.
Do we know if tagging failed during the initial checks in the tagBuild call or later in the tag task?
tagBuild
The error from koji for that case was TagError: Package perl-CGI not in list for eln-modular-updates-candidate so it's failing during the initial checks of tagBuild.
TagError: Package perl-CGI not in list for eln-modular-updates-candidate
Hmm. Related to #1722. Not quite a dup because this seems to be actually getting an error on the tagBuild call.
It's a little weird for mbs to get this "package not in list" error because mbs should be managing that list. It suggests something else is going wrong. That said, the error should certainly be noticed and reported clearly.
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/koji/mbs/issues/1713
Please continue any further discussion there.