kbd uses _Generic since version 2.2.90 and https://github.com/legionus/kbd/commit/da5feb8fd90c3a0df9d505d4604c629d051d3d7d However, _Generic is not available until gcc 4.9: https://gcc.gnu.org/wiki/C11Status As a result, build with gcc 4.8 fails on: setleds.c:352:3: warning: implicit declaration of function '_Generic' [-Wimplicit-function-declaration] ndefflags = BITMASK_SET(BITMASK_UNSET(odefflags, ndef), nval); ^ setleds.c:22:2: error: expected expression before 'unsigned' unsigned char: (unsigned char)(~(x)) \ ^ Fixes: - http://autobuild.buildroot.org/results/b74ecdda44543da1d47fa2c027fb046a3ca1e2d1 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> [yann.morin.1998@free.fr: propagate the MMU dependency to the comment] Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>