The current version of media-sound/lilypond in stable is 2.0.3. The lilypond website http://lilypond.org/web/ lists 2.4.5 as the current stable release. Please version bump the stable lilypond in portage to 2.4.5. Reproducible: Always Steps to Reproduce:
Oh, one thing I forgot, was that fixing this bug will also fix bug #82928.
Is anyone looking after lilypond at all now? Even the ~x86 version is 2.5.2 which is much older than the stable version on the lilypond website.
My bad. Bug #97574 seems to suggest that work is in progress.
Closing this bug as #97574 is the fix and the way forward.