Impossible to edit builds in side-tag updates

[ernestask]

Splitting from https://github.com/fedora-infra/bodhi/issues/4002#issuecomment-624506966, because otherwise it will get buried.

There is currently no way to swap out builds in side-tag updates, which forces packagers to waste time and bump release numbers just to be able to create new updates or, even worse, use build root overrides.

Using the CLI to try to hack something results in:

ERROR: The release of the update is composed by Bodhi, i.e. follows the normal update workflow. Please build packages normally, using build root overrides as required, and edit the update accordingly with these new builds.

The contents of the message are gibberish to the uninitiated.

[mohanboddu]

Other errors while editing an update are listed in https://pagure.io/releng/issue/9857

[juhp]

Isn't it possible to refresh the update with the sidetag refresh button now?