anchor.diff:  
   let
     inherit (stdenv.lib)
  -    enFlag
  -    wtFlag;
  +    boolEn
  +    boolWt;
   
     version = "2.2.0";
   in
  
positive.code:     "--localstatedir=/var"
      "--sysconfdir=/etc"
      "--disable-mallinfo"
      (enFlag "libpaper" (libpaper != null) null)
      (enFlag "libusb" (libusb != null) null)
      #--enable-tcp-wrappers
      (enFlag "acl" (acl != null) null)
      (enFlag "dbus" (dbus != null) null)
      "--enable-shared"
      "--disable-libtool-unsupported"
      "--disable-debug"
  
negative.code:     # --with-rundir=/run/cups
      # XXX: flag is not a proper boolean, build fails with optim enabled
      #"--without-optim"
      "--${boolWt (systemd_lib != null)}-systemd"
      "--with-languages=all"
      # --with-cups-user=lp
      # --with-cups-group=lp
  