anchor.diff:    { supportedSystems ? [ "x86_64-linux" "x86_64-darwin" ]
     , scrubJobs ? true
     , dconfigs ? [ "testnet_staging" "travis" ]
  +  , cardano ? { outPath = ./.; rev = "abcdef"; }
   }:
   with import (fixedNixpkgs + "/pkgs/top-level/release-lib.nix") { inherit supportedSystems scrubJobs; packageSet = import ./.; };
   with builtins;
  
positive.code:   };
    mkJobs = dconfig: systems: listToAttrs (map (mkJob dconfig) systems);
    mkDconfigs = dconfig: let
      cardano = import ./. { inherit pkgs dconfig; };
      jobs = mkJobs dconfig supportedSystems;
    in {
      name = dconfig;
  
negative.code:   lib = import ./lib.nix;
    pkgs = import lib.fetchNixPkgs { config={}; };
    mkJob = dconfig: system: let
      jobs = import ./. { inherit system dconfig; gitrev = cardano.rev; };
    in {
      name = system;
      value = {
  