anchor.diff:  , avahi
   , dbus
   , gnutls
  -, kerberos
  +#, kerberos
   , libgcrypt
   , libpaper
   , libusb
  
positive.code:     "--disable-debug-printfs"
      "--disable-unit-tests"
      #"--enable-relro"
      (enFlag "gssapi" (kerberos != null) null)
      "--enable-threads"
      (enFlag "ssl" (
        gnutls != null
  
negative.code:     avahi
      dbus
      gnutls
      #kerberos
      libgcrypt
      libpaper
      libusb
  