clang -O2  -Wall -Wextra -Werror=implicit-function-declaration unistd/unlinkat.c -o unistd/unlinkat -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm  -lintl
../out/minix/basic/unistd/unlinkat.o: In function `main':
unistd/unlinkat.c:(.text+0x3f2): undefined reference to `unlinkat'
clang: error: linker command failed with exit code 1 (use -v to see invocation)