pyside2-designer crashes: undefined symbol: _ZdlPvm, version Qt_5

open pyside2-designer, click 'Create', then it crashes with:

```
/home/me/.local/lib/python3.8/site-packages/PySide2/designer: symbol lookup error: /home/me/.local/lib/python3.8/site-packages/PySide2/designer: undefined symbol: _ZdlPvm, version Qt_5
```

Following the answer on Stackoverflow, the problem disappears when the PySide2 shared library path is supplied:
```
LD_LIBRARY_PATH=$HOME/.local/lib/python3.8/site-packages/PySide2/Qt/lib: pyside2-designer
```
but I suppose the environment should have been taken care of somewhere in the launcher scripts.