pitivi fails to build with Python 3.8.0b1.

The build no longer links to libpython, resulting in undefined references to Python API like Py_InitializeEx.
Code that embeds Python (rather than building an extension module) needs to pass `--embed` to any `python3-config --libs` invocation to build with Python 3.8.
More information: 
https://docs.python.org/3.8/whatsnew/3.8.html#debug-build-uses-the-same-abi-as-release-build

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.8/fedora-rawhide-x86_64/00927336-pitivi/

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

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.