clang -O2   -Wall -Wextra -Werror=implicit-function-declaration unistd/readlinkat.c -o unistd/readlinkat -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm   -lintl
../out/minix/basic/unistd/readlinkat.o: In function `main':
unistd/readlinkat.c:(.text+0x3e4): undefined reference to `symlinkat'
unistd/readlinkat.c:(.text+0x40b): undefined reference to `readlinkat'
unistd/readlinkat.c:(.text+0x444): undefined reference to `unlinkat'
unistd/readlinkat.c:(.text+0x4c5): undefined reference to `unlinkat'
clang: error: linker command failed with exit code 1 (use -v to see invocation)