anchor.diff:      "--zshcompletiondir=${placeholder "out"}/share/zsh/site-functions"
       "--bashcompletiondir=${placeholder "out"}/share/bash-completion/completions"
       "--infodir=${placeholder "info"}/share/info"
  -  ] ++ optional (!withEmacs) "--without-emacs"
  -    ++ optional (withEmacs) "--emacslispdir=${placeholder "emacs"}/share/emacs/site-lisp"
  -    ++ optional (isNull ruby) "--without-ruby";
  +  ] ++ lib.optional (!withEmacs) "--without-emacs"
  +    ++ lib.optional withEmacs "--emacslispdir=${placeholder "emacs"}/share/emacs/site-lisp"
  +    ++ lib.optional (isNull ruby) "--without-ruby";
   
     # Notmuch doesn't use autoconf and consequently doesn't tag --bindir and
     # friends
     setOutputFlags = false;
     enableParallelBuilding = true;
     makeFlags = [ "V=1" ];
  -
   
     outputs = [ "out" "man" "info" ] ++ lib.optional withEmacs "emacs";
   
  
positive.code:     mkdir -p test/test-databases
      ln -s ${test-database} test/test-databases/database-v1.tar.xz
    '';
    doCheck = !stdenv.hostPlatform.isDarwin && (versionAtLeast gmime.version "3.0.3");
    checkTarget = "test";
    checkInputs = [
      which dtach openssl bash
  
negative.code:     doxygen                   # (optional) api docs
      pythonPackages.sphinx     # (optional) documentation -> doc/INSTALL
      texinfo                   # (optional) documentation -> doc/INSTALL
    ] ++ lib.optional withEmacs emacs;
  
    buildInputs = [
      gnupg                     # undefined dependencies
  