Dagger generates invalid code

Dagger generates invalid code if auto-value annotations are present, but auto-value processor is not configured as an annotation processor. This can lead to compile failures that are hard to understand.

Also the error message @AutoAnnotation is a necessary dependency if @MapKey(unwrapValue = false). Add a dependency on com.google.auto.value:auto-value:<current version> in MapKeyValidator is misleading, because

• AutoAnnotation is not in artifact auto-value but in auto-value-annotations
• Having AutoAnnotation on the classpath does not imply that auto-value is also working as an annotation processor

See demo

[bcorso]

Sorry, I considered this more of an issue with improper setup of auto-value (on the user side) due to a misleading error message (on the Dagger side). Understandably, you could argue that the user shouldn’t have to add these dependencies manually, but this is currently working as intended to avoid adding the auto-value dependencies to all users who aren’t using the feature.

That said, I’m currently discussing with the team on ways we can improve this experience, e.g. by reevaluating adding the auto-value dependency (which should be pretty small now that the annotations have their own artifact), shading auto-value into Dagger, or just reimplementing that part ourselves.

I’m happy to leave this issue open until we make a decision on that.

[h908714124]

Seems like this ticket was closed, but the problem was not fixed.