complicated jsonschema and importlib_metadata co-dependencies

[gtsambos]

When I fetched the code on the master branch and attempted to run some of the tests in python/tests, I kept getting this error (even after ensuring that the modules in requirements.txt were all installed and the git submodules were up to date)

AttributeError: module 'jsonschema' has no attribute 'validators'

Doing some Googling, I learn that 'validators' have only been part of jsonschema since version 3.2.0 (see here), so I installed the latest version of jsonschema with pip (v 3.3.0). But this time, I get a different error when I run a Python test:

  File "/miniconda3/lib/python3.7/site-packages/jsonschema/__init__.py", line 33, in <module>
    import importlib_metadata as metadata
ModuleNotFoundError: No module named 'importlib_metadata'

This is odd, since the module is definitely installed. Some brief googling indicates that this error message might be related to jsonschema as well.

Anyway, I don't entirely know what the solution is, but I thought I'd flag it as a problem! At the very least, there should be specific versions of jsonschema specified in development.txt.

(also btw, when I upgraded jsonschema, I got the following warning. I don't know if it's related to this problem or not)

Successfully built pyrsistent
ERROR: python-jsonschema-objects 0.3.5 has requirement jsonschema~=2.3, but you'll have jsonschema 3.2.0 which is incompatible.

[jeromekelleher]

This does look weird. We should definitely pin the version of jsonschema both in requirements.txt and in setup.py. If it's a new version that causes issues we should consider using the features.

[benjeffery]

@gtsambos can you try using the requirements file in requirements/CI?

[jeromekelleher]

@gtsambos, any update on this one, or do you think we can close the issue?

[gtsambos]

Hi @jeromekelleher @benjeffery, sorry for leaving this hanging, I just forgot about it! I haven't been using the computer that I had this issue on for a little while, but will be getting it back at the end of this week -- I will check up on this again then.

[jeromekelleher]

Closing this one, as it seems likely it was a problem in the environment for the machine.