anchor.diff:              os = "linux";
             });
             impure = runCommand "${baseName}-config.json"
  -            { buildInputs = [ jq ]; }
  +            { nativeBuildInputs = [ jq ]; }
               ''
                  jq ".created = \"$(TZ=utc date --iso-8601="seconds")\"" ${pure} > $out
               '';
  
positive.code:   }:
      runCommand "docker-layer-${name}" {
        inherit baseJson contents extraCommands;
        buildInputs = [ jshon rsync tarsum ];
      }
      ''
        mkdir layer
  
negative.code:   # We need to sum layer.tar, not a directory, hence tarsum instead of nix-hash.
    # And we cannot untar it, because then we cannot preserve permissions ecc.
    tarsum = runCommand "tarsum" {
      nativeBuildInputs = [ go ];
    } ''
      mkdir tarsum
      cd tarsum
  