$ make install PREFIX=$HOME/yetris SCOREDIR=$HOME/yetris
# Compiling src/engine.c...
# Compiling src/piece.c...
# Compiling src/game.c...
# Compiling src/main.c...
# Compiling src/timer.c...
src/timer.c:70: error: conflicting types for ‘timer_delta_us’
src/timer.h:72: error: previous declaration of ‘timer_delta_us’ was here
make: *** [obj/timer.o] Error 1