clang -O2 -Wall -Wextra -Werror=implicit-function-declaration time/timer_create.c -o time/timer_create -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lintl ../out/minix/basic/time/timer_create.o: In function `main': time/timer_create.c:(.text+0x33e): undefined reference to `timer_create' clang: error: linker command failed with exit code 1 (use -v to see invocation)