anchor.diff:      wiringPiD = mkSubProject {
         subprj = "wiringPiD";
         buildInputs = [
  +        libxcrypt
           passthru.wiringPi
           passthru.devLib
         ];
  
positive.code:     gpio = mkSubProject {
        subprj = "gpio";
        buildInputs = [
          passthru.wiringPi
          passthru.devLib
        ];
  
negative.code:     inherit mkSubProject;
      wiringPi = mkSubProject {
        subprj = "wiringPi";
        buildInputs = [
          libxcrypt
        ];
      };
      devLib = mkSubProject {
        subprj = "devLib";
  