micropipenv fails to build with Python 3.9.0b1.

It seems to be an issue with pip 20.1 rather than Python 3.9.0b1. The package was not tracked by Koschei, so I've enabled it now and it should tell us if it also fails on Python 3.8.

=================================== FAILURES ===================================
_____________________ test_parse_requirements2pipfile_lock _____________________

    def test_parse_requirements2pipfile_lock():
        """Test parsing of requirements.txt into their Pipfile.lock representation."""
        work_dir = os.path.join(_DATA_DIR, "parse", "pip-tools")
        with cwd(work_dir):
>           pipfile_lock = micropipenv._requirements2pipfile_lock()

tests/test_micropipenv.py:322: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

    def _requirements2pipfile_lock():  # type: () -> Dict[str, Any]
        """Parse requirements.txt file and return its Pipfile.lock representation."""
        requirements_txt_path = _traverse_up_find_file("requirements.txt")
    
        pip_session = PipSession()
        finder = _instantiate_package_finder(pip_session)
    
        result = {}  # type: Dict[str, Any]
        for requirement in parse_requirements(filename=requirements_txt_path, session=PipSession(), finder=finder):
            entry = {}  # type: Dict[str, Any]
    
>           if not requirement.editable:
E           AttributeError: 'ParsedRequirement' object has no attribute 'editable'

micropipenv.py:359: AttributeError
_______________ test_parse_requirements2pipfile_lock_not_locked ________________

    def test_parse_requirements2pipfile_lock_not_locked():
        """Test raising an exception when requirements.txt do not state all packages as locked."""
        work_dir = os.path.join(_DATA_DIR, "parse", "requirements")
        with cwd(work_dir):
            with pytest.raises(micropipenv.PipRequirementsNotLocked):
>               micropipenv._requirements2pipfile_lock()

tests/test_micropipenv.py:578: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

    def _requirements2pipfile_lock():  # type: () -> Dict[str, Any]
        """Parse requirements.txt file and return its Pipfile.lock representation."""
        requirements_txt_path = _traverse_up_find_file("requirements.txt")
    
        pip_session = PipSession()
        finder = _instantiate_package_finder(pip_session)
    
        result = {}  # type: Dict[str, Any]
        for requirement in parse_requirements(filename=requirements_txt_path, session=PipSession(), finder=finder):
            entry = {}  # type: Dict[str, Any]
    
>           if not requirement.editable:
E           AttributeError: 'ParsedRequirement' object has no attribute 'editable'

micropipenv.py:359: AttributeError
============== 2 failed, 56 passed, 15 deselected in 0.68 seconds ==============

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01396195-micropipenv/

For all our attempts to build micropipenv with Python 3.9, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/package/micropipenv/

Testing and mass rebuild of packages is happening in copr. You can follow these instructions to test locally in mock if your package builds with Python 3.9:
https://copr.fedorainfracloud.org/coprs/g/python/python3.9/

Let us know here if you have any questions.

Python 3.9 will be included in Fedora 33. To make that update smoother, we're building Fedora packages with early pre-releases of Python 3.9.
A build failure prevents us from testing all dependent packages (transitive [Build]Requires), so if this package is required a lot, it's important for us to get it fixed soon.
We'd appreciate help from the people who know this package best, but if you don't want to work on this now, let us know so we can try to work around it on our side.