anchor.diff:  { stdenv
  -, autoreconfHook
   , fetchurl
  -, intltool
   , lib
   
   , babl
   , cairo
   , exiv2
  -, ffmpeg
  +, ffmpeg_3-4
   , gdk-pixbuf
   , gexiv2
   , glib
  
positive.code:     "--disable-maintainer-mode"
      "--${boolEn (gobject-introspection != null)}-introspection"
      "--disable-glibtest"
      "--${boolEn (vala != null)}-vala"
      "--without-mrg"
      "--${boolWt (gexiv2 != null)}-gexiv2"
      "--${boolWt (cairo != null)}-cairo"
  
negative.code:     babl
      cairo
      exiv2
      ffmpeg_3-4
      gdk-pixbuf
      gexiv2
      glib
  