Currently issues with parsing class files are only issued on DEBUG level (https://github.com/eclipse/sisu.inject/blob/a9752361662edac045f16129a49e1a8b625aa604/org.eclipse.sisu.inject/src/main/java/org/eclipse/sisu/space/SpaceScanner.java#L115). As this is a frequent cause of trouble (https://lists.apache.org/thread/6wxrhlkrqsl7wgr730xd50h55t7ff0vy) this should at least optionally lead to an exception or at least log entry with ERROR level.