ecj is only installed as a versioned binary e.g. ecj-3.2. There should also be a symlink 'ecj'. This should either be configurable, or slotting should be removed and one ecj symlink used. I can't see any reason why ecj would need a slot. Reproducible: Always
*** Bug 230619 has been marked as a duplicate of this bug. ***
This has now been resolved with the addition of eselect-ecj.
eselect-ecj committed. Thanks Chewi.