Latest pyyaml expecting class but getting function

Hi, I am not sure if the issue is with you or pyyaml but I just completed a clean build and get the following error when running infer_simple.py example with pyyaml version 5.1

yaml.constructor.ConstructorError: while constructing a Python instance expected a class, but found <class 'builtin_function_or_method'> in "<unicode string>", line 3, column 20: BBOX_XFORM_CLIP: !!python/object/apply:numpy.core ...

I rolled the version back to 4.2 and it works fine: pip install pyyaml==4.2b2

System information

• Operating system: 18.04
• Compiler version: 3.6
• CUDA version: 10
• cuDNN version: 9
• NVIDIA driver version: 415
• GPU models (for all devices if they are not all the same): 1080ti
• PYTHONPATH environment variable: NA
• python --version output: 3.6.7
• Anything else that seems relevant: ?

[matthhan]

I encountered the same error and solved the problem by changing yaml_load = yaml.load to yaml_load = lambda x: yaml.load(x, Loader=yaml.Loader) in detectron/utils/env.py Not sure if this is a valid solution in every case, because yaml.load might be used elsewhere in the codebase. However, in my case this was a good workaround.

[haoransh]

Another workaround is to roll back the pyyaml to 3.12 version, since the detectron seems built on that version initially. A similar problem is in https://github.com/facebookresearch/DensePose/issues/216