AssertionError: Invalid type <class 'NoneType'> for key WEIGHT_DECAY_BIAS

Hi, WEIGHT_DECAY_BIAS parameter in detectron2/config/defaults.py that exists for Detectron v1 training causes the mentioned error when you try to import the file. If you change the None value with 0 (line 560), the bug seems to be fixed but I am not sure if that change breaks something else.

Instructions To Reproduce the 🐛 Bug:

1. In a Python terminal: from detectron2.config import configurable

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/detectron2/config/__init__.py", line 2, in <module>
    from .compat import downgrade_config, upgrade_config
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/detectron2/config/compat.py", line 28, in <module>
    from .defaults import _C
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/detectron2/config/defaults.py", line 560, in <module>
    _C.SOLVER.WEIGHT_DECAY_BIAS = None  # None means following WEIGHT_DECAY
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/fvcore/common/config.py", line 148, in __setattr__
    super().__setattr__(name, val)
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/yacs/config.py", line 155, in __setattr__
    _assert_with_logging(
  File "/storage/miniconda/envs/myenv/lib/python3.9/site-packages/yacs/config.py", line 521, in _assert_with_logging
    assert cond, msg
AssertionError: Invalid type <class 'NoneType'> for key WEIGHT_DECAY_BIAS; valid types = {<class 'float'>, <class 'list'>, <class 'str'>, <class 'int'>, <class 'bool'>, <class 'tuple'>}

Environment:

I am using torch 1.10.0 with prebuilt detectron2 0.6 with CUDA 11.1. The mentioned codepiece still exists in the main branch, so I don’t think this is related with my environment.

[submagr]

@zhao-yiqun try following in your environment:

pip uninstall yacs
pip install yacs --upgrade

For some reason, upgrading yacs alone was not sufficient for me.

[hiyyg]

Hey, I solved it by updating yacs to >= 0.1.8.