Qutip fails to install on Python 3.11.0

Bug Description

Installing qutip with pip on Python 3.11 fails at the “Getting the requirements to build the wheel” stage.

Potentially related to these changes in packaging, introduced in the latest update to 22.0.

Code to Reproduce the Bug

pip install qutip --no-cache-dir

Code Output

Collecting qutip
  Downloading qutip-4.7.0.tar.gz (3.6 MB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3.6/3.6 MB 18.2 MB/s eta 0:00:00
  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  error: subprocess-exited-with-error
  
  × Getting requirements to build wheel did not run successfully.
  │ exit code: 1
  ╰─> [20 lines of output]
      Traceback (most recent call last):
        File "/Users/hsilver/opt/miniconda3/envs/py311/lib/python3.11/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 351, in <module>
          main()
        File "/Users/hsilver/opt/miniconda3/envs/py311/lib/python3.11/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 333, in main
          json_out['return_val'] = hook(**hook_input['kwargs'])
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/Users/hsilver/opt/miniconda3/envs/py311/lib/python3.11/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 118, in get_requires_for_build_wheel
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/private/var/folders/h9/04p7x4ds0hvfmd80jt8gx3kc0000gn/T/pip-build-env-dzdmg7x6/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 338, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=['wheel'])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/private/var/folders/h9/04p7x4ds0hvfmd80jt8gx3kc0000gn/T/pip-build-env-dzdmg7x6/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 320, in _get_build_requires
          self.run_setup()
        File "/private/var/folders/h9/04p7x4ds0hvfmd80jt8gx3kc0000gn/T/pip-build-env-dzdmg7x6/overlay/lib/python3.11/site-packages/setuptools/build_meta.py", line 335, in run_setup
          exec(code, locals())
        File "<string>", line 247, in <module>
        File "<string>", line 46, in process_options
        File "<string>", line 130, in _determine_version
      AttributeError: module 'packaging.version' has no attribute 'LegacyVersion'
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.

Expected Behaviour

Should install qutip without errors.

Your Environment

QuTip Version: 4.7.0
Python version: 3.11.0
`packaging` version: 22.0
`pip` version: 22.3.1

Additional Context

I explicitly mention Python 3.11 because I failed to replicate the issue on a fresh Python 3.10 environment.

EDIT: Looking deeper into the qutip built distributions, the reason why this is failing only for Python 3.11 is because earlier versions of Python have built distributions, unlike Python 3.11.

This indicates that building the wheel from source is generally broken, which I confirmed by forcing an installation from source on Python 3.10 with

pip install qutip --no-cache-dir --no-binary :all:

[hodgestar]

QuTiP 4.7.1 has been released to PyPI – https://pypi.org/project/qutip/4.7.1/ – and pip install qutip now works for me on Python 3.11.

[hodgestar]

I’m busy checking builds in #2046, and hopefully once those are running successfully, we can release. It’s the usual dance of figuring out which versions of SciPy and numpy to build for.