While working on CLAIRDEV-41, I hit a point where I didn't trust the test fixtures and wanted to rebuild them.

This led me down a rabbit hole, finding the following:

1. In addition to module information, Container API (pyxis) rpm manifests are missing epoch information.
2. Those rpm manifests do contain epoch information for the source packages, which our rpm package does not find.
3. Our current source package mapping is based on the source rpm file name, which (by convention only) is a NVRA string.
4. There's no other information recorded about the source in an rpm.
5. Source and binary rpms may have different names (we knew this) and may have different {{EVR}}s (we assumed this); however, that does mean we can't know the source epoch.

Taken together, this means we should remove the source package guessing from rpm and work with upstream to add the facility to track that. See the GitHub Discussion link.