False positives on CI for major charm library updates

[lucabello]

When a charm has multiple versions of a library, the CI will (wrongly) think that the charm needs to bump the major version.

As noticed in our Tempo coordinator¹, this is what happens:

• a charm has both:
  • charms.tempo_k8s.v1.tracing
  • charms.tempo_k8s.v2.tracing
• CI sees v1 and doesn't notice v2, adding the library to the list of charm libs that need upgrading

The correct behavior should be either:

• when detecting an old major version (e.g., v1), don't mention the library needs to upgraded if the latest version (e.g., v2) is also present;
• possibly, if there are other charm libraries that need a major upgrade, add a separate list of "multiple major versions have been detected; please make sure this is intentional".

Footnotes

1. https://github.com/canonical/tempo-coordinator-k8s-operator/issues/3 ↩