anchor.diff:      # Force using nixpkgs dependencies
       sed -i '/MODULES += contrib/d' make/include/main.defs
       sed -i '/PKG_CONFIG_PATH=/d' gtk/module.rules
  -    sed -i 's/^[[:space:]]*\(meson\|ninja\)[[:space:]]*= ToolProbe.*$//g' make/configure.py
  +    sed -e 's/^[[:space:]]*\(meson\|ninja\|nasm\)[[:space:]]*= ToolProbe.*$//g' \
  +        -e '/    ## Additional library and tool checks/,/    ## MinGW specific library and tool checks/d' \
  +        -i make/configure.py
     '';
   
     configureFlags = [
  
positive.code:   # look at ./make/configure.py search "enable_nvenc"
      ++ lib.optional stdenv.isLinux nv-codec-headers;
  
    # NOTE: 2018-12-25: v1.2.0 now requires cmake dep
    # (default distribution bundles&builds 3rd party libs),
    # don't trigger cmake build
    dontUseCmakeConfigure = true;
    # cp: cannot create regular file './internal_defaults.json': File exists
    enableParallelBuilding = false;
  
    preConfigure = ''
      patchShebangs scripts
  
  
negative.code:   };
  
    nativeBuildInputs = [
      python2 pkgconfig autoconf automake libtool m4
    ] ++ lib.optionals useGtk [ intltool wrapGAppsHook ];
  
    buildInputs = [
  