anchor.diff:  
     exec = name: { user, command, ... }:
       let
  +      cc = "${pkgs.gcc}/bin/gcc -Wall -Wextra -Werror -s -std=gnu99 -O2";
         uid = toString config.users.users.${user}.uid;
         gid = uid;
         src = pkgs.writeText "${name}.c" ''
           #include <unistd.h>
           #include <grp.h>
           #include <pwd.h>
  -        #include <stdio.h> 
  +        #include <stdio.h>
           #include <stdlib.h>
           #include <sys/types.h>
   
  
positive.code:           return EXIT_FAILURE;
          }
        '';
      in pkgs.runCommand name {} "gcc -Wall -Wextra -Werror -s -std=gnu99 -O2 ${src} -o $out";
  
    cliapp = submodule({name, ...}:
    {
  
negative.code: 
  let
  
    inherit (lib)
      concatMapStrings filterAttrs mapAttrs mapAttrsToList mkOption unique ;
    inherit (lib.types)
  