clang -O2  -Wall -Wextra -Werror=implicit-function-declaration sys_msg/msgsnd.c -o sys_msg/msgsnd -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm  -lintl
../out/minix/basic/sys_msg/msgsnd.o: In function `main':
sys_msg/msgsnd.c:(.text+0x3d8): undefined reference to `msgget'
sys_msg/msgsnd.c:(.text+0x411): undefined reference to `msgsnd'
../out/minix/basic/sys_msg/msgsnd.o: In function `cleanup':
sys_msg/msgsnd.c:(.text+0x4cb): undefined reference to `__msgctl50'
../out/minix/basic/sys_msg/msgsnd.o: In function `on_signal':
sys_msg/msgsnd.c:(.text+0x5ff): undefined reference to `__msgctl50'
clang: error: linker command failed with exit code 1 (use -v to see invocation)