clang -O2  -Wall -Wextra -Werror=implicit-function-declaration sys_stat/mkdirat.c -o sys_stat/mkdirat -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm  -lintl
../out/minix/basic/sys_stat/mkdirat.o: In function `main':
sys_stat/mkdirat.c:(.text+0x421): undefined reference to `mkdirat'
clang: error: linker command failed with exit code 1 (use -v to see invocation)