Getting Logcat output from Robolectric tests

By default, Logcat output (from Log calls) doesn't seem to go anywhere when running tests under Robolectric. To see it, the log stream has to be set:

ShadowLog.stream = System.out;

However, there might be undesired spurious output from Android or third-party components. One way to deal with this would be to set the stream to a custom one that filters the output in some way before writing it to standard out. Alternatively, you could provide a custom ShadowLog implementation that filters by tag or call stack. One of my projects checks to see if the current thread's stack trace has a class in the app's package right before Log. To avoid unnecessary checks, the result on whether the log is "internal" is cached by tag.