anchor.diff:  let
     coreosImageRelease = "794.1.0";
     coreosImageSystemdVersion = "222";
  -  stage1Flavour = "coreos";
  +
  +  # TODO: track https://github.com/coreos/rkt/issues/1758 to allow "host" flavor.
  +  stage1Flavours = [ "coreos" ];
   
   in stdenv.mkDerivation rec {
  -  version = "0.10.0";
  +  version = "0.11.0";
     name = "rkt-${version}";
     BUILDDIR="build-${name}";
   
  
positive.code:   preConfigure = ''
      ./autogen.sh
      configureFlagsArray=(
        --with-stage1=${stage1Flavour}
        --with-stage1-image-path=$out/stage1-${stage1Flavour}.aci
        --with-coreos-local-pxe-image-path=${stage1BaseImage}
        --with-coreos-local-pxe-image-systemd-version=v${coreosImageSystemdVersion}
      );
    '';
  
  
negative.code:       rev = "v${version}";
        owner = "coreos";
        repo = "rkt";
        sha256 = "0qdg3m99viymran9n7rxywwbqr3xqgk8r7hsk6nj3liwqsx6agiv";
    };
  
    stage1BaseImage = fetchurl {
  