PySide2 does not link to bundle Qt libraries by default

On Fedora 28, when I install PySide2 into a new virtual environment (using `python3 -m venv` with the system Python 3.6.6), I see the following in the Python REPL:

// code placeholder
Python 3.6.6 (default, Jul 19 2018, 14:25:17) 
[GCC 8.1.1 20180712 (Red Hat 8.1.1-5)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from PySide2 import QtCore
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: /usr/lib64/libQt5Core.so.5: version `Qt_5.12' not found (required by /home/user/tmp/pyside/lib64/python3.6/site-packages/PySide2/QtCore.abi3.so)
>>> 

If I run

export LD_LIBRARY_PATH=$PWD/lib/python3.6/site-packages/PySide2/Qt/lib:$LD_LIBRARY_PATH 

from the root of the virtual environment and then start the REPL again, I see:

Python 3.6.6 (default, Jul 19 2018, 14:25:17) 
[GCC 8.1.1 20180712 (Red Hat 8.1.1-5)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from PySide2 import QtCore
>>> 

I see this for both the version on PyPI and the latest version on download.qt.io (PySide2==5.12.0a1.dev1541316155).

I am not that familiar with packaging shared libraries into a Python wheel like this. What mechanism is supposed to be used so that the Python bindings link to the appropriate Qt libraries? I have also been working with PySide2 on Arch Linux without a problem, but it is possible that PySide2 is still linking to the system Qt libraries there and they just happen to work, unlike the Fedora ones.

(By the way, it is really cool how the wheel packages the Qt libraries - I hope that it will be possible to pip install my projects without any dependencies external to Python and without needing to modify environment variables).