Error while running pip install git+https://github.com/cvxgrp/sigopt

Question

C:\Users\user>pip install git+https://github.com/cvxgrp/sigopt
Defaulting to user installation because normal site-packages is not writeable
Collecting git+https://github.com/cvxgrp/sigopt
  Cloning https://github.com/cvxgrp/sigopt to c:\users\user\appdata\local\temp\pip-req-build-0pgpc486
  Running command git clone --filter=blob:none --quiet https://github.com/cvxgrp/sigopt 'C:\Users\user\AppData\Local\Temp\pip-req-build-0pgpc486'
  Resolved https://github.com/cvxgrp/sigopt to commit 6f3bd83a1eee963bb7b089843a8cacf5b867ea61
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error

  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [34 lines of output]
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "C:\Users\user\AppData\Local\Temp\pip-req-build-0pgpc486\setup.py", line 28, in <module>
          setup(
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\__init__.py", line 108, in setup
          return distutils.core.setup(**attrs)
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\_distutils\core.py", line 147, in setup
          _setup_distribution = dist = klass(attrs)
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\dist.py", line 488, in __init__
          _Distribution.__init__(
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\_distutils\dist.py", line 283, in __init__
          self.finalize_options()
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\dist.py", line 911, in finalize_options
          for ep in sorted(loaded, key=by_order):
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\dist.py", line 910, in <lambda>
          loaded = map(lambda e: e.load(), filtered)
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\setuptools\_vendor\importlib_metadata\__init__.py", line 208, in load
          module = import_module(match.group('module'))
        File "C:\Program Files\Python39\lib\importlib\__init__.py", line 127, in import_module
          return _bootstrap._gcd_import(name[level:], package, level)
        File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
        File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
        File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
        File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
        File "<frozen importlib._bootstrap_external>", line 850, in exec_module
        File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\py2app\build_app.py", line 37, in <module>
          from py2app.create_appbundle import create_appbundle
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\py2app\create_appbundle.py", line 9, in <module>
          from py2app.util import make_exec, makedirs, mergecopy, mergetree, skipscm
        File "C:\Users\user\AppData\Roaming\Python\Python39\site-packages\py2app\util.py", line 5, in <module>
          import fcntl
      ModuleNotFoundError: No module named 'fcntl'
      [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 wanted to install the sigopt library in the git repo https://github.com/cvxgrp/sigopt but the pip install sigopt installs other sigopt library. So I tried doing it directly from git but it throws fnctl error, which doesn't exist for windows. A couple of posts like Error: No module named 'fcntl' suggest using waitress library. I couldn't do it for git+url kind of command. I tried the solutions in the post linked above but I am still getting the same error. The code in the git repo is in python2 while I use python3. Is there an issue with that? How do I go about this?