Activator - how to recompile with -Xlint:unchecked?

Question

I run my play application using the run command from inside activator. When I open the index page, after compiling the sources, the console prints

[warn] Note: Some input files use unchecked or unsafe operations.
[warn] Note: Recompile with -Xlint:unchecked for details.

How do I do that? How do I recompile with that parameter? I've tried running activator with activator -J-Xlint:unchecked and JAVA_OPTS="-Xlint:unchecked" activator, both of which resulted in

Unrecognized option: -Xlint:unchecked
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

Answer 1

Add this to your build.sbt:

javacOptions += "-Xlint:unchecked"