By default, all logs sent to android.util.Log are swallowed by Robolectric. It can be fixed by settings ShadowLog.stream to something like System.out.

Enabling it all the time would however spam the output of the other tests and making it harder to find errors.

A rule would be an easy way to enable logging for specific tests, but if we could cache logs during tests and only display them on failures, it would be nice to have it applied on all of them. That would likely require playing with the TestRunner in that case.