Repository: Unbabel/COMET
Issue: proposed python version (3.6) throws error when installing requirements (3.7 works)
Root cause: Environment Incompatibility

Running pip install -r requirements with proposed python3.6 results in:  RuntimeError: Python version >= 3.7 required, when trying to install the fairseq module. Installation runs smoothly with 3.7.

Full error trace below:

  ```
Collecting fairseq==0.9.0 (from -r requirements.txt (line 7))
  Cache entry deserialization failed, entry ignored
  Cache entry deserialization failed, entry ignored
  Downloading https://files.pythonhosted.org/packages/67/bf/de299e082e7af010d35162cb9a185dc6c17db71624590f2f379aeb2519ff/fairseq-0.9.0.tar.gz (306kB)
    100% |████████████████████████████████| 307kB 2.0MB/s 
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 154, in save_modules
        yield saved
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 195, in setup_context
        yield
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 250, in run_setup
        _execfile(setup_script, ns)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 45, in _execfile
        exec(code, globals, locals)
      File "/tmp/easy_install-s58jkscl/numpy-1.20.1/setup.py", line 30, in <module>
        self.__include_dirs = []
    RuntimeError: Python version >= 3.7 required.
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-5bklbiad/fairseq/setup.py", line 161, in <module>
        zip_safe=False,
      File "/usr/lib/python3/dist-packages/setuptools/__init__.py", line 128, in setup
        _install_setup_requires(attrs)
      File "/usr/lib/python3/dist-packages/setuptools/__init__.py", line 123, in _install_setup_requires
        dist.fetch_build_eggs(dist.setup_requires)
      File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 513, in fetch_build_eggs
        replace_conflicting=True,
      File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 774, in resolve
        replace_conflicting=replace_conflicting
      File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 1057, in best_match
        return self.obtain(req, installer)
      File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 1069, in obtain
        return installer(requirement)
      File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 580, in fetch_build_egg
        return cmd.easy_install(req)
      File "/usr/lib/python3/dist-packages/setuptools/command/easy_install.py", line 698, in easy_install
        return self.install_item(spec, dist.location, tmpdir, deps)
      File "/usr/lib/python3/dist-packages/setuptools/command/easy_install.py", line 724, in install_item
        dists = self.install_eggs(spec, download, tmpdir)
      File "/usr/lib/python3/dist-packages/setuptools/command/easy_install.py", line 909, in install_eggs
        return self.build_and_install(setup_script, setup_base)
      File "/usr/lib/python3/dist-packages/setuptools/command/easy_install.py", line 1177, in build_and_install
        self.run_setup(setup_script, setup_base, args)
      File "/usr/lib/python3/dist-packages/setuptools/command/easy_install.py", line 1163, in run_setup
        run_setup(setup_script, args)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 253, in run_setup
        raise
      File "/usr/lib/python3.6/contextlib.py", line 99, in __exit__
        self.gen.throw(type, value, traceback)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 195, in setup_context
        yield
      File "/usr/lib/python3.6/contextlib.py", line 99, in __exit__
        self.gen.throw(type, value, traceback)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 166, in save_modules
        saved_exc.resume()
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 141, in resume
        six.reraise(type, exc, self._tb)
      File "/usr/lib/python3/dist-packages/setuptools/_vendor/six.py", line 685, in reraise
        raise value.with_traceback(tb)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 154, in save_modules
        yield saved
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 195, in setup_context
        yield
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 250, in run_setup
        _execfile(setup_script, ns)
      File "/usr/lib/python3/dist-packages/setuptools/sandbox.py", line 45, in _execfile
        exec(code, globals, locals)
      File "/tmp/easy_install-s58jkscl/numpy-1.20.1/setup.py", line 30, in <module>
        self.__include_dirs = []
    RuntimeError: Python version >= 3.7 required.

```