It breaks multi-part flags. CFLAGS="-march=pentium4 -O2 -fprefetch-loop-arrays --param max-unrolled-insns=2000" gcc --param -D_GNU_SOURCE -D_REENTRANT -I../../include -O2 -Wall -Winline -Wno-uninitialized -Wshadow -fprefetch-loop-arrays -march=pentium4 -pipe max-unrolled-insns=2000 -c libTutf.c -o libTutf.o gcc: cannot specify -o with -c or -S and multiple compilations %.o: %.c $(call echo-and-compile,$(CC_BIN) $(sort $(CC_FLAGS) $(CC_FLAGS_$@)) -c $< -o,$@) @$(ECHO_E) ' ifeq ($$(CC_BIN) $$(sort $$(CC_FLAGS) $$(CC_FLAGS_$@)),$(CC_BIN) $(sort $(CC_FLAGS) $(CC_FLAGS_$@)))\n'\ ' FILES_UP_TO_DATE += $@\n'\ 'endif' > .$@.flags && \ $(echo-done)
e-mailed upstream but they seem kind of dead the makerules file is kind of ugly so i'm not gonna look into it more :p