pytest_operator_cache prevents non-cached build_charm

[paulomach]

Plugin pytest_operator_cache will always try to use cached charm file.
Maybe fallback (here?) to use pytest_operator.build_charm?

Use-case for the mysql upgrade rollback test, where we need to refresh with a faulty charm.
The test and the error

[github-actions]

https://warthogs.atlassian.net/browse/DPE-2433

[carlcsaposs-canonical]

This is by design—so that caching fails with an error instead of failing silently.

Also, how would the plugin differentiate between two different builds of the same charm? i.e. two calls to ops_test.build_charm(".")—should the cache be used in both, one, or neither of those cases?

It looks like we need to add an option to build without the cache (maybe an ops_test.build_charm_without_cache), but I don't think it should be an automatic fallback

[paulomach]

I see your point.
I like the suggestion of having an explicit method ops_test.build_charm_without_cache that frontends to pytest_operator's ops_test.build_charm

[carlcsaposs-canonical]

Found another solution: unzip the .charm file, modify the charm, and rezip the .charm file

This prevents adding 1 hour+ to the upgrade integration test (from using a non-cached build)

[carlcsaposs-canonical]

In the future, if it's necessary to build multiple versions of the same charm using the cached workflow, it may be possible to add this functionality to the workflow. This might be a better solution if the modifications become more complex (e.g. modifying the charmcraft.yaml file), but for simple modifications, unzipping & rezipping the .charm file seems much simpler