anchor.diff:      sha256 = "1hwkliyb8fjrz5sw9fcisssig0jkdxzhccw0ld0l9a10q1l9mqhp";
     };
   
  -  buildInputs = [ sqlite pkgconfig xapian glib gmime texinfo emacs guile
  -                  gtk3 webkit libsoup icu ];
  +  buildInputs =
  +    [ sqlite pkgconfig xapian glib gmime texinfo emacs guile libsoup icu ]
  +    ++ stdenv.lib.optional withMug [ gtk3 webkit ];
   
     preBuild = ''
       # Fix mu4e-builddir (set it to $out)
  
positive.code:   '';
  
    # Install mug and msg2pdf
    postInstall = ''
      cp -v toys/msg2pdf/msg2pdf $out/bin/
      cp -v toys/mug/mug $out/bin/
    '';
  
negative.code: { fetchurl, stdenv, sqlite, pkgconfig, xapian, glib, gmime, texinfo, emacs, guile
  , gtk3, webkit, libsoup, icu, withMug ? false /* doesn't build with current gtk3 */ }:
  
  stdenv.mkDerivation rec {
    version = "0.9.9.5";
  