Running the debugger, I can confirm that Distribution.name is None in this case:

```
~ $ python3.10 -m pip-run -q rinohtype -- -m pdb -m rinoh --help
WARNING: You are using pip version 21.1.1; however, version 21.1.2 is available.
You should consider upgrading via the '/usr/local/bin/python3.10 -m pip install --upgrade pip' command.
Uncaught exception. Entering post mortem debugging
Running 'cont' or 'step' will restart the program
> /Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/re.py(187)sub()
-> return _compile(pattern, flags).sub(repl, string, count)
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/pdb.py", line 1709, in main
    pdb._runmodule(mainpyfile)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/pdb.py", line 1541, in _runmodule
    mod_name, mod_spec, code = runpy._get_module_details(module_name)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/runpy.py", line 146, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/runpy.py", line 110, in _get_module_details
    __import__(pkg_name)
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/__init__.py", line 41, in <module>
    from . import resource
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/resource.py", line 205, in <module>
    from .template import DocumentTemplate
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/template.py", line 42, in <module>
    from .stylesheets import sphinx
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/stylesheets/__init__.py", line 42, in <module>
    .format(stylesheet.description, stylesheet))
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/style.py", line 670, in __str__
    for name, entry_point in self.installed_resources:
  File "/var/folders/c6/v7hnmq453xb6p2dbz1gqc6rr0000gn/T/pip-run-w0xovt3h/rinoh/resource.py", line 54, in installed_resources
    for entry_point in ilm.entry_points()[cls.entry_point_group]:
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py", line 979, in entry_points
    return SelectableGroups.load(eps).select(**params)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py", line 437, in load
    ordered = sorted(eps, key=by_group)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py", line -1, in <genexpr>
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/_itertools.py", line 16, in unique_everseen
    k = key(element)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py", line 600, in _normalized_name
    return Prepared.normalize(self.name)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py", line 841, in normalize
    return re.sub(r"[-_.]+", "-", name).lower().replace('-', '_')
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/re.py", line 187, in sub
    return _compile(pattern, flags).sub(repl, string, count)
TypeError: expected string or bytes-like object

(Pdb) string is None
True
(Pdb) u
> /Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py(841)normalize()
-> return re.sub(r"[-_.]+", "-", name).lower().replace('-', '_')
(Pdb) u
> /Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/importlib/metadata/__init__.py(600)_normalized_name()
-> return Prepared.normalize(self.name)
(Pdb) self.name is None
True
```