clang -O2  -Wall -Wextra -Werror=implicit-function-declaration unistd/dup3.c -o unistd/dup3 -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm  -lintl
../out/minix/basic/unistd/dup3.o: In function `main':
unistd/dup3.c:(.text+0x30e): undefined reference to `dup3'
clang: error: linker command failed with exit code 1 (use -v to see invocation)