PySide2.QtUiTools cannot be imported if installed via pip3

If you attempt to load PySide2 via pip (which installs the 5.12.1 development version by default), then use a .ui file, this is what happens:

>>> from PySide2.QtUiTools import QUiLoader
Traceback (most recent call last):
{{ File "<stdin>", line 1, in <module>}}
ImportError: /usr/local/lib/python3.6/dist-packages/PySide2/QtUiTools.abi3.so: undefined symbol: _ZN8Shiboken27setErrorAboutWrongArgumentsEP7_objectPKc

As you can see, that's kind of a bummer.

Let me know if I can provide any additional details. This is on Ubuntu 18.04 LTS, with PySide installed via "sudo pip3 install PySide2".