Irusak,
Can you elaborate? I have game.libretro, game.libretro.snes9x, and libretro-snes9x in my virutal/mediacenter/package.mk right below peripheral.joystick in the stock LE-master virtual/medicacenter/package.mk. All build properly. I can find game.libretro.snes9x.so in /usr/lib/kodi/addons/game.libretro.snes9x/game.libretro.snes9x.so. It appears the package.mk for the lot of the addons have:
cp -L $PKG_BUILD/.install_pkg/usr/lib/kodi/addons/$PKG_NAME/$ADDONSO $ADDON_BUILD/$PKG_ADDON_ID/
but wouldn't that resolve the error kodi is reporting? I thought the $ADDON_BUILD/$PKG_ADDON_ID var would be usr/share/kodi/addons/game.libretro.snes9x/ in this case. I apologize if I'm out of my league here. All I can say where is the donate beer icon on the site.