test_lexicon_external misses etc/sample_lexicon.xml

[Mic92]

$ python setup.py test
======================================================================
ERROR: test_lexicon_external (tests.test_ssml.SSMLTestCase)
Test <lexicon> from URI
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 1503, in open_local_file
    stats = os.stat(localfile)
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmp.YVEnEy28Oj/gruut/etc/sample_lexicon.xml'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/tmp.YVEnEy28Oj/gruut/tests/test_ssml.py", line 379, in test_lexicon_external
    results = [
  File "/tmp/tmp.YVEnEy28Oj/gruut/tests/test_ssml.py", line 379, in <listcomp>
    results = [
  File "/tmp/tmp.YVEnEy28Oj/gruut/gruut/__init__.py", line 79, in sentences
    graph, root = text_processor(text, lang=lang, ssml=ssml, **process_args)
  File "/tmp/tmp.YVEnEy28Oj/gruut/gruut/text_processor.py", line 440, in __call__
    return self.process(*args, **kwargs)
  File "/tmp/tmp.YVEnEy28Oj/gruut/gruut/text_processor.py", line 972, in process
    load_lexicon(lexicon_uri, inline_lexicons[lexicon_id])
  File "/tmp/tmp.YVEnEy28Oj/gruut/gruut/utils.py", line 239, in load_lexicon
    with urlopen(uri, context=ssl_context) as response:
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 214, in urlopen
    return opener.open(url, data, timeout)
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 517, in open
    response = self._open(req, data)
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 534, in _open
    result = self._call_chain(self.handle_open, protocol, protocol +
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 494, in _call_chain
    result = func(*args)
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 1481, in file_open
    return self.open_local_file(req)
  File "/nix/store/rppr9s436950i1dlzknbmz40m2xqqnxc-python3-3.9.9/lib/python3.9/urllib/request.py", line 1520, in open_local_file
    raise URLError(exp)
urllib.error.URLError: <urlopen error [Errno 2] No such file or directory: '/tmp/tmp.YVEnEy28Oj/gruut/etc/sample_lexicon.xml'>