Unable to install requirements for examples

[albo437]

I'm trying to run pip install -r examples/requirements.txt, which is pip install -r examples/requirements.in now but keep getting the following error

Collecting gym==0.21 (from stable_baselines3->-r requirements.in (line 12))
  Using cached gym-0.21.0.tar.gz (1.5 MB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [3 lines of output]
      /home/alvaro/anaconda3/envs/meltingPot/lib/python3.11/site-packages/setuptools/_distutils/dist.py:270: UserWarning: Unknown distribution option: 'tests_require'
        warnings.warn(msg)
      error in gym setup command: 'extras_require' must be a dictionary whose values are strings or lists of strings containing valid project/version requirement specifiers.
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

I can't run python self_play_train.py or python sb3_train.py.

[sriramsowmithri9807]

Hey @albo437

I ran into a bit of a snag trying to get the examples running with pip install -r examples/requirements.in. It looks like gym==0.21 throws a fit on Python 3.11 because the newer version of setuptools is way stricter about how extras_require is formatted in setup.py.

Basically, gym is using an old format that modern setuptools doesn't like anymore, which is why the metadata generation fails.

The quick fix that worked for me: Just downgrade setuptools for a second before running the requirements install. It makes the installer a bit more "forgiving" with the old Gym code:

Bash

pip install "setuptools<65.0"
pip install -r examples/requirements.in

Once I did that, self_play_train.py and sb3_train.py both fired up perfectly. Hope this helps anyone else hitting the same wall!