anchor.diff:      "--without-graphviz"
       "--without-lua"
       "--${boolWt (ffmpeg != null)}-libavformat"
  -    #"--${boolWt (v4l_lib != null)}-libv4l"
  -    "--without-libv4l"
  +    "--${boolWt (v4l_lib != null)}-libv4l"
       "--${boolWt (lcms2 != null)}-lcms"
       "--without-libspiro"
       "--${boolWt (exiv2 != null)}-exiv2"
  
positive.code:     "--${boolWt (gdk-pixbuf != null)}-gdk-pixbuf"
      "--without-lensfun"
      "--${boolWt (librsvg != null)}-librsvg"
      # Requires --with-libv4l
      #"--${boolWt (v4l_lib != null)}-libv4l2"
      "--without-libv4l2"
      "--${boolWt (openexr != null)}-openexr"
      "--without-sdl"
      "--${boolWt (libraw != null)}-libraw"
  
negative.code:     libwebp
      openexr
      pango
      v4l_lib
    ];
  
    configureFlags = [
  