Avahi.InvalidServiceTypeError: Invalid service type

[edward-jw-yu]

Ubuntu2004, mdns 1.4.3
gcc -o mdns mdns.c
./mdns --service test_mdnsmw_service1._http._tcp.local. --port 10001 --hostname vbox2.local
./mdns --service test_mdnsmw_service1._dns-sd._tcp.local. --port 10001 --hostname vbox2.local
./mdns --service test._http._tcp.local.
opening avahi-discover came out the following:
Browsing domain 'local' on -1.-1 ...
Browsing for services of type '' in domain 'test._http._tcp.local' on 2.1 ...
ERROR:dbus.connection:Exception in handler for D-Bus signal:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 232, in maybe_handle_message
self._handler(*args, **kwargs)
File "/usr/bin/avahi-discover", line 182, in new_service_type
b = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, self.server.ServiceBrowserNew(interface, protocol, stype, domain, dbus.UInt32(0))), avahi.DBUS_INTERFACE_SERVICE_BROWSER)
File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 147, in call
**keywords)
File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 653, in call_blocking
message, timeout)
DBusException: org.freedesktop.Avahi.InvalidServiceTypeError: Invalid service type
Browsing for services of type '' in domain 'test._http._tcp.local' on 2.0 ...
ERROR:dbus.connection:Exception in handler for D-Bus signal:
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 232, in maybe_handle_message
self._handler(*args, **kwargs)
File "/usr/bin/avahi-discover", line 182, in new_service_type
b = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, self.server.ServiceBrowserNew(interface, protocol, stype, domain, dbus.UInt32(0))), avahi.DBUS_INTERFACE_SERVICE_BROWSER)
File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 147, in call
**keywords)
File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 653, in call_blocking
message, timeout)
DBusException: org.freedesktop.Avahi.InvalidServiceTypeError: Invalid service type

[mjansson]

You should not handle DNS-SD like that - the library takes care of service discovery for you (which is handled by a _services._dns-sd._udp.local. query, see RFC in https://datatracker.ietf.org/doc/html/rfc6763)

Your service should probably not be test_mdnsmw_service1._http._tcp.local. - the _http._tcp.local. is the service name normally used for HTTP.

Also, hostname should be without the local suffix.