anchor.diff:    lib = import ./lib.nix;
     pkgs = import lib.fetchNixPkgs { config={}; };
     mkJob = dconfig: system: let
  -    jobs = import ./. { inherit system dconfig; };
  +    jobs = import ./. { inherit system dconfig; gitrev = cardano.rev; };
     in {
       name = system;
       value = {
  
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:   { 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;
  