`AttributeError` with invalid flag added in `pytest_addoption`
Author: The-CompilerCreated Oct 15, 2025Updated Sep 28, 2026
Labelstype: bug
With Python 3.13.7 and pytest-8.4.2, doing this in a conftest.py:
def pytest_addoption(parser):
parser.addoption("shuffle") # without --results in:
Traceback (most recent call last):
...
File ".../conftest.py", line 2, in pytest_addoption
parser.addoption("shuffle")
~~~~~~~~~~~~~~~~^^^^^^^^^^^
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 102, in addoption
self._anonymous.addoption(*opts, **attrs)
~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 406, in addoption
option = Argument(*opts, **attrs)
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 300, in __init__
self._set_opt_strings(names)
~~~~~~~~~~~~~~~~~~~~~^^^^^^^
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 349, in _set_opt_strings
raise ArgumentError(
~~~~~~~~~~~~~^
f"invalid long option string {opt!r}: "
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"must start with --, followed by non-dash",
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
self,
^^^^^
)
^
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 268, in __init__
self.option_id = str(option)
~~~^^^^^^^^
File "/usr/lib/python3.13/site-packages/_pytest/config/argparsing.py", line 362, in __repr__
args += ["dest: " + repr(self.dest)]
^^^^^^^^^
AttributeError: 'Argument' object has no attribute 'dest'Source: pytest-dev/pytest