Remove "No main class detected" warning in SBT

Question

I have a multi-module SBT project. Some of the modules produce JARs with main classes and can be started with java -jar but most don't.

However when I run (or compile, or anything else) one of the modules (sbt foo/run) I get a warning per library module.

[warn] No main class detected

How can I remove those warnings?

Answer 1

This warning is considered a bug in sbt 0.13.7 and it will be removed in sbt 0.13.8.