Currently, WikibaseLexeme extension does not seem to have phan checks enabled. This means, among other things, that if its dependencies change, it may not be properly updated. This recently caused T215503 for example.
We need to enable phan check (extension-phan template) in Lexeme's CI build. Due to dependencies on CirrusSearch, we may need to take special measures (see Wikibase and WikibaseCirrusSearch) to make it work properly.
Rules that do not initially work should be disabled and they will be tackled separately.
Any terrible things that are spotted while doing this should not be done as part of this ticket.
The job should be Voting and Passing on CI.