>>> Compiling source in /var/tmp/portage/dev-java/jsr223-1.0-r1/work ... * Using javac for compilation javac: directory not found: build Usage: javac <options> <source files> use -help for a list of possible options * ERROR: dev-java/jsr223-1.0-r1 failed: ecj automatically creates the directory to let's check it exists in the eclass to automatically spot this.
Dealt with in the following commit: https://github.com/monsieurp/gentoo/commit/c0861a45e481b810ef882916dbbc84245264d1a0 I'll leave this bug open until the PR is merged.
After some discussion, we've decided not to do this. ejavac is supposed to be a thin wrapper around javac and javac is expected to fail in this situation. ejavac is most often used in java-pkg-simple where the directory is already created for you anyway.