anchor.diff:  
       boehmgc = boehmgc_nixUnstable;
   
  +    patches = [ installNlohmannJsonPatch ];
  +
       inherit storeDir stateDir confDir;
   
     });
  
positive.code:     ];
    });
  
  in rec {
  
    nix = nixStable;
  
negative.code: 
      boehmgc = boehmgc_nixUnstable;
  
      patches = [ installNlohmannJsonPatch ];
  
      inherit storeDir stateDir confDir;
    });
  
  