If kdenlive is run from the terminal, it informs that quite a lot of
plugins are blacklisted. The 'erros' look something like:
```
"videostab" is blacklisted
"videostab2" is blacklisted
"burningtv" is blacklisted
...
...
...
```

I was under the impression that this was a packaging issue on our part. But
turns out, these plugins are blacklisted upstream:
https://invent.kde.org/multimedia/kdenlive/-/blob/master/data/blacklisted_effects.txt