Should display error when plugin not applied about anvil HOT 5 CLOSED

Yes, I agree. The annotations are added as api dependency, because they're actually exposed (on the public type). But I see how this can cause issues downstream like you described.

from anvil.

Added by who, if given module doesnt apply the plugin?

from anvil.

You probably apply the plugin in one of the library modules that you import. The Gradle plugin adds this dependency.

from anvil.

Yea I add it in :base, and do I include :base in the given module. But I include it as implementation project(":base") -- doesn't that mean "Include base but none of its transitive dependencies?", i.e. not api, which would include transitive deps.

from anvil.

No, that's not what implementation means, see https://docs.gradle.org/current/userguide/java_library_plugin.html#sec:java_library_separation

from anvil.