python-colcon-bundle fails to build with Python 3.8.0b1.

+ /usr/bin/python3 -m pytest --ignore=test/test_flake8.py test
============================= test session starts ==============================
platform linux -- Python 3.8.0b1, pytest-4.4.1, py-1.8.0, pluggy-0.11.0
rootdir: /builddir/build/BUILD/colcon-bundle-0.0.13, inifile: setup.cfg
collected 17 items

test/test_bundlefile.py F.                                               [ 11%]
test/test_pip3_installer.py ....                                         [ 35%]
test/test_pip_installer.py ....                                          [ 58%]
test/test_python_bundle.py s.                                            [ 70%]
test/test_setup.py .                                                     [ 76%]
test/test_utilities.py ....                                              [100%]

=================================== FAILURES ===================================
________________________ TestBundlefile.test_bundlefile ________________________

self = <test.test_bundlefile.TestBundlefile object at 0x7fca0a535af0>

    def test_bundlefile(self):
        bundle_path = os.path.join(self.tmpdir, 'test.mba')
        json_file = os.path.join(self.tmpdir, 'file')
        with open(json_file, 'w') as f:
            f.write(json.dumps(json_data))
    
        blocksize_file = os.path.join(self.tmpdir, 'blocksize_file')
        with open(blocksize_file, 'wb') as f:
            f.write(bytearray(tarfile.BLOCKSIZE))
    
        large_file = os.path.join(self.tmpdir, 'large_file')
        with open(large_file, 'wb') as f:
            large_file_size = 12 + tarfile.BLOCKSIZE * 1000
            f.write(bytearray(large_file_size))
    
        dep_archive = os.path.join(self.tmpdir, 'dependencies.tar.gz')
        with tarfile.open(dep_archive, 'w:gz') as a:
            a.add(json_file, arcname='file')
    
        other_archive = os.path.join(self.tmpdir, 'other.tar.gz')
        with tarfile.open(other_archive, 'w:gz') as a:
            a.add(json_file, arcname='file2')
    
        with Bundle(name=bundle_path, mode='w') as bundle:
            bundle.add_overlay_archive(dep_archive)
            bundle.add_overlay_archive(other_archive)
            bundle.add_overlay_archive(blocksize_file)
            bundle.add_overlay_archive(large_file)
    
        metadata_path = os.path.join(self.tmpdir, 'metadata.tar.gz')
        with tarfile.open(bundle_path, 'r:') as bundle:
            members = bundle.getmembers()
            assert 'version' == members[0].name
            assert 'metadata.tar.gz' == members[1].name
            assert 'pad' == members[2].name
            assert 'dependencies.tar.gz' == members[3].name
            # Validate the overlays start at 4MB
>           assert 4 * 1024 * 1024 == members[3].offset
E           AssertionError: assert ((4 * 1024) * 1024) == 4195328
E            +  where 4195328 = <TarInfo 'dependencies.tar.gz' at 0x7fca0a511ac0>.offset

test/test_bundlefile.py:60: AssertionError
=============================== warnings summary ===============================
test/test_python_bundle.py::test_bundle
  /usr/lib/python3.8/site-packages/_pytest/python.py:174: PytestWarning: Coroutine functions are not natively supported and have been skipped.
  You need to install a suitable plugin for your async framework, for example:
    - pytest-asyncio
    - pytest-trio
    - pytest-tornasync
    warnings.warn(PytestWarning(msg.format(pyfuncitem.nodeid)))

-- Docs: https://docs.pytest.org/en/latest/warnings.html
========== 1 failed, 15 passed, 1 skipped, 1 warnings in 0.49 seconds ==========

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.8/fedora-rawhide-x86_64/00940840-python-colcon-bundle/

For all our attempts to build python-colcon-bundle with Python 3.8, see:
https://copr.fedorainfracloud.org/coprs/g/python/python3.8/package/python-colcon-bundle/

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 3.8:
https://copr.fedorainfracloud.org/coprs/g/python/python3.8/

Let us know here if you have any questions.