Hi all, FYI, we just merged a patch that fails a build if there is a scala compiler warning (if it is not deprecation warning).
In the past, many compiler warnings are actually caused by legitimate bugs that we need to address. However, if we don't fail the build with warnings, people don't pay attention at all to the warnings (it is also tough to pay attention since there are a lot of deprecated warnings due to unit tests testing deprecated APIs and reliance on Hadoop on deprecated APIs). Note that ideally we should be able to mark deprecation warnings as errors as well. However, due to the lack of ability to suppress individual warning messages in the Scala compiler, we cannot do that (since we do need to access deprecated APIs in Hadoop).
