Ubuntu 20.04 LTS python 3.9 "glasgow --version" crash while enumerating plugin requirements

gistfile1.txt

ewen@parthenon:~$ glasgow --version
> /src/glasgow/software/glasgow/support/plugin.py(18)_entry_points()
-> for distribution in importlib.metadata.distributions():
(Pdb) b 25
Breakpoint 1 at /src/glasgow/software/glasgow/support/plugin.py:25
(Pdb) c
> /src/glasgow/software/glasgow/support/plugin.py(25)_entry_points()
-> yield entry_point
(Pdb) display entry_point
display entry_point: EntryPoint(name='analyzer', value='glasgow.applet.interface.analyzer:AnalyzerApplet', group='glasgow.applet')
(Pdb) c
> /src/glasgow/software/glasgow/support/plugin.py(25)_entry_points()
-> yield entry_point
display entry_point: EntryPoint(name='audio-dac', value='glasgow.applet.audio.dac:AudioDACApplet', group='glasgow.applet')  [old: EntryPoint(name='analyzer', value='glasgow.applet.interface.analyzer:AnalyzerApplet', group='glasgow.applet')]
(Pdb) c
> /src/glasgow/software/glasgow/support/plugin.py(25)_entry_points()
-> yield entry_point
display entry_point: EntryPoint(name='audio-yamaha-opx', value='glasgow.applet.audio.yamaha_opx:AudioYamahaOPxApplet [http]', group='glasgow.applet')  [old: EntryPoint(name='audio-dac', value='glasgow.applet.audio.dac:AudioDACApplet', group='glasgow.applet')]
(Pdb) c
calling requirement.marker.evalulate({"extra": <re.Match object; span=(1, 5), match='http'>})
Traceback (most recent call last):
  File "/usr/local/share/pipx/bin/glasgow", line 8, in <module>
    sys.exit(main())
  File "/src/glasgow/software/glasgow/cli.py", line 903, in main
    exit(loop.run_until_complete(_main()))
  File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete
    return future.result()
  File "/src/glasgow/software/glasgow/cli.py", line 486, in _main
    args = get_argparser().parse_args()
  File "/src/glasgow/software/glasgow/cli.py", line 279, in get_argparser
    add_applet_arg(p_run, mode="interact", required=True)
  File "/src/glasgow/software/glasgow/cli.py", line 124, in add_applet_arg
    for handle, metadata in GlasgowAppletMetadata.all().items():
  File "/src/glasgow/software/glasgow/support/plugin.py", line 93, in all
    return {ep.name: cls(ep) for ep in _entry_points(group=cls.GROUP_NAME)}
  File "/src/glasgow/software/glasgow/support/plugin.py", line 93, in <dictcomp>
    return {ep.name: cls(ep) for ep in _entry_points(group=cls.GROUP_NAME)}
  File "/src/glasgow/software/glasgow/support/plugin.py", line 103, in __init__
    self.requirements = _requirements_for_optional_dependencies(
  File "/src/glasgow/software/glasgow/support/plugin.py", line 37, in _requirements_for_optional_dependencies
    if requirement.marker and requirement.marker.evaluate({"extra": dependency}):
  File "/usr/local/share/pipx/venvs/glasgow/lib/python3.9/site-packages/packaging/markers.py", line 252, in evaluate
    return _evaluate_markers(self._markers, current_environment)
  File "/usr/local/share/pipx/venvs/glasgow/lib/python3.9/site-packages/packaging/markers.py", line 157, in _evaluate_markers
    lhs_value, rhs_value = _normalize(lhs_value, rhs_value, key=environment_key)
  File "/usr/local/share/pipx/venvs/glasgow/lib/python3.9/site-packages/packaging/markers.py", line 131, in _normalize
    return tuple(canonicalize_name(v) for v in values)
  File "/usr/local/share/pipx/venvs/glasgow/lib/python3.9/site-packages/packaging/markers.py", line 131, in <genexpr>
    return tuple(canonicalize_name(v) for v in values)
  File "/usr/local/share/pipx/venvs/glasgow/lib/python3.9/site-packages/packaging/utils.py", line 47, in canonicalize_name
    value = _canonicalize_regex.sub("-", name).lower()
TypeError: expected string or bytes-like object
ewen@parthenon:~$ 

FTR, the smallest fix for this seems to be to cooerce the re.Match() (ie, match group) "string" to be a real string before we try to use it. Ie in _requirements_for_optional_dependencies() check the dependency, and if necessary str()ify it.

@@ -27,7 +31,13 @@ def _requirements_for_optional_dependencies(distribution, depencencies):
     requirements = map(packaging.requirements.Requirement, distribution.requires)
     selected_requirements = set()
     for dependency in depencencies:
+        import re
+        if isinstance(dependency, re.Match):
+            dependency = dependency.group(0)
+
         for requirement in requirements: