If a task (like KSP does for example) manages their own internal caches, how should such a directory be marked in Gradle? KSP today marks it as

Internal

which isn’t good because when the task output is restored from cache it becomes invalid. One option is to mark it as

LocalState

but that wipes the cache upon cache restoration which maybe isn’t ideal. It could be marked as an output but it’s also needed as an input (though changes to it should not cause task invalidation so it should not be marked as an input). But is this safe? Obviously whatever is put in there cannot contain absolute path and such for that to work

I don't think outputs are deleted before task execution what's in this internal dir?

I don’t know yet, still looking into it

Yes, local state is what you need in that case