# Buggy code
def __init__(self, envname, config, factors, reader):
    #: test environment name
    self.envname = envname
    #: global tox config object
    self.config = config
    #: set of factors
    self.factors = factors
    self._reader = reader
    self._missing_subs = []
    """Holds substitutions that could not be resolved.

        Pre 2.8.1 missing substitutions crashed with a ConfigError although this would not be a
        problem if the env is not part of the current testrun. So we need to remember this and
        check later when the testenv is actually run and crash only then.
        """


# Traceback (AttributeError)
tox -vv
using tox.ini: /home/jayvdb/projects/tox/my-tox-tests/tests/tox.ini (pid 23538)
removing /home/jayvdb/projects/tox/my-tox-tests/tests/.tox/log
[wikimedia] tox-wikimedia is enabled
Traceback (most recent call last):
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/bin/tox", line 8, in <module>
sys.exit(cmdline())
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/tox/session/__init__.py", line 44, in cmdline
main(args)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/tox/session/__init__.py", line 65, in main
config = load_config(args)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/tox/session/__init__.py", line 81, in load_config
config = parseconfig(args)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/tox/config/__init__.py", line 281, in parseconfig
pm.hook.tox_configure(config=config)  # post process config object
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/hooks.py", line 286, in __call__
return self._hookexec(self, self.get_hookimpls(), kwargs)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/manager.py", line 93, in _hookexec
return self._inner_hookexec(hook, methods, kwargs)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/manager.py", line 84, in <lambda>
self._inner_hookexec = lambda hook, methods, kwargs: hook.multicall(
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/callers.py", line 208, in _multicall
return outcome.get_result()
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/callers.py", line 80, in get_result
raise ex[1].with_traceback(ex[2])
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/pluggy/callers.py", line 187, in _multicall
res = hook_impl.function(*args)
File "/home/jayvdb/.cache/tox/my-tox-tests/py38-tox3_20-other/lib/python3.8/site-packages/tox_wikimedia/__init__.py", line 93, in tox_configure
if dep in cdep.name:
AttributeError: 'str' object has no attribute 'name'

# Fixed code
def __init__(self, envname, config, factors, reader):
    #: test environment name
    self.envname = envname
    #: global tox config object
    self.config = config
    #: set of factors
    self.factors = factors
    self._reader = reader
    self._missing_subs = {}
    """Holds substitutions that could not be resolved.

        Pre 2.8.1 missing substitutions crashed with a ConfigError although this would not be a
        problem if the env is not part of the current testrun. So we need to remember this and
        check later when the testenv is actually run and crash only then.
        """