anchor.diff:  let
     inherit (lib)
       boolEn
  +    boolWt
  +    optionals
       optionalString;
   
     sources = {
  
positive.code: , gst-plugins-base
  , gstreamer
  , libdrm
  , mesa_noglu
  , pango
  , wayland
  , xorg
  
  , channel
  }:
  
negative.code:     gobject-introspection
      gst-plugins-base
      gstreamer
      opengl-dummy
      pango
    ] ++ optionals opengl-dummy.egl [
      libdrm
      wayland
    ] ++ optionals (opengl-dummy.glx || opengl-dummy.egl) [
      libx11
      libxcomposite
      libxdamage
      libxext
      libxfixes
      libxrandr
    ];
  
    postPatch =
  