anchor.diff:  
   assert libx11 != null ->
     xorg.libXcursor != null
  -  && xorg.libXi != null
  -  && xorg.libXinerama != null
  -  && xorg.libXrandr != null
  -  && xorg.libXrender != null;
  +  && xorg.libXi != null;
   
   let
     inherit (lib)
  
positive.code:     libxdamage
      libxext
      libxfixes
      libxkbcommon
      mesa_noglu
      pango
      rest
  
negative.code:   ] ++ optionals (libx11 != null) [
      xorg.libXcursor
      xorg.libXi
    ];
  
    configureFlags = [
  