ValueError: Expected a string for URI

[dragonxtek]

After install pathspider I tried to run it, but I couldn't:

pspdr measure -i wlp0s20f3 ecn < examples/webtest.ndjson > results.ndjson
WARNING:pr2modules.ipdb.main:Deprecation warning https://docs.pyroute2.org/ipdb_toc.html
WARNING:pr2modules.ipdb.main:Deprecation warning https://docs.pyroute2.org/ipdb_toc.html
WARNING:pr2modules.ipdb.main:Deprecation warning https://docs.pyroute2.org/ipdb_toc.html
INFO:pathspider:activating spider...
INFO:pathspider:starting pathspider
INFO:pathspider:Creating observer
Traceback (most recent call last):
File "/usr/local/bin/pspdr", line 33, in
sys.exit(load_entry_point('pathspider==2.1.0.dev0', 'console_scripts', 'pspdr')())
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/cmd/base.py", line 62, in handle_args_wrapper
handle_args(sys.argv)
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/cmd/base.py", line 57, in handle_args
args.cmd(args)
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/cmd/measure.py", line 87, in run_measurement
spider.start()
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/base.py", line 399, in start
self.observer = self.create_observer()
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/base.py", line 159, in create_observer
return Observer(self.libtrace_uri,
File "/usr/local/lib/python3.10/dist-packages/pathspider-2.1.0.dev0-py3.10.egg/pathspider/observer.py", line 96, in init
self._trace = libtrace.trace(lturi) # pylint: disable=no-member
ValueError: Expected a string for URI