games-emulation/81-libretro
A port of the EightyOne ZX81 Emulator to libretro
USE Flags
custom-cflags
Global: Build with user-specified CFLAGS (unsupported)
debug
Global: Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see http://www.gentoo.org/proj/en/qa/backtraces.xml