ejavac takes care of (-target -source parameters selected java compiler etc.) especailly the first is important since it will cause the jar not to work with a jre prior to jdk its built with Reproducible: Always Expected Results: should use ejavac
This is qt's domain.
Should now be fixed in -r1 ebuild. Thanks for the report. You can add comments or thoughts regarding qtjambi to bug #181120, which is where we're tracking the progress.