message: Add strerror to error test
diff: #include <unistd.h>
  #include <stdio.h>
  +#include <string.h>
  #include <errno.h>
  int main(int argc, char** argv) {
  chdir("nonexistent");
  - printf("errno: %d\n", errno);
  + printf("errno: %d = %s\n", errno, strerror(errno));
  }
  