Musepack codec is now supported by VLC but since libmpc is not installed, VLC does not support it. A musepack USE flag have to be added and so, libmpc will be installed if necessary. Reproducible: Always Steps to Reproduce:
Created attachment 106109 [details, diff] Patch to vlc-0.8.6-r1.ebuild to add a musepack USE flag The patch is tested and working. At least on x86 system.
Use flag added, thanks for reporting :) In fact it was worse than that, musepack support was enabled as soon as you had libmpcdec enabled, thus it was an automagic dep