android - Room "Not sure how to convert a Cursor to this method's return type": which method?

Question

Error:Not sure how to convert a Cursor to this method's return type
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
Compilation failed; see the compiler error output for details.

Using Room I'm getting this error and I'd like to find out which method causes it.

I have multiple DAOs, with approximately 60 methods in total, and this error just popped up after adding a method (copy&pasted from another one that worked perfectly, just changed the field to set).

I could post the whole class of DAOs, but I'm asking for a way to know which method failed. I tried with Run with --stacktrace, Run with --info and --debug option, but none of these show any valuable information.

The method I added is a @Query UPDATE with Int return type, as suggested in the documentation

UPDATE or DELETE queries can return void or int. If it is an int, the value is the number of rows affected by this query.

EDIT: I'd like to add that I tried deleting the method, bringing the DAO back to the working state, but it still gives me this error.

EDIT2: Adding gradle console output because unreadable in comments:

error: Not sure how to convert a Cursor to this method's return type
error: Not sure how to convert a Cursor to this method's return type
2 errors

:app:compileDebugJavaWithJavac FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

* Get more help at https://help.gradle.org

BUILD FAILED in 22s

Answer 1

Recently I've had the same problem but I was using Coroutines within the Dao function, e.g.:

@Query("SELECT * FROM Dummy")
suspend fun get(): LiveData<List<Dummy>>

And was unable to compile, but after removing the suspend everything worked just fine. It's not needed when returning LiveData. suspend and LiveData seem not to work together (as of now).