carla - segmentation fault

Hello,

I am on slackware64 stable 14.2 and I am trying to install carla from the sbo slackbuild.

I tried with the version 2.1 of carla in https://slackbuilds.org/repository/1.../?search=carla and also with the new version 2.3.0 (downloaded the source code), but I always get a segmentation fault:

giovanni@slackserver:~$ carla
LRDF Support not available (LADSPA-RDF will be disabled)
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-giovanni'
Carla 2.3.0 started, status:
Python version: 3.7.2
Qt version: 5.14.0
PyQt version: 5.14.1
Binary dir: /usr/lib64/carla
Resources dir: /usr/share/carla/resources
Frontend pixel ratio is 1.0
libjack.so.0 loaded successfully!
Segmentation fault

The strange thing is that carla says Qt version: 5.14.0 and PyQt version: 5.14.1, but actually I don't have those versions installed.

My installed versions are:

root@slackserver:~# slpkg -f qt5

Packages with matching name [ qt5 ]

[ installed ] [ 15M ] - qbittorrent-qt5-4.2.5-x86_64-1_SBo
[ installed ] [ 341M ] - qt5-5.12.8-x86_64-1_SBo
[ installed ] [ 37M ] - qt5-webkit-5.9.1-x86_64-1alien
[ installed ] [ 770K ] - quazip-qt5-0.8.1-x86_64-1_SBo

and

root@slackserver:~# slpkg -f PyQt

Packages with matching name [ PyQt ]

[ installed ] [ 40M ] - PyQt-4.11.4-x86_64-1
[ installed ] [ 29M ] - python3-PyQt5-5.13.2-x86_64-2_SBo

Do you have any idea/suggestion about how to fix this problem?
I really need to use carla for LMMS.

Best regards,
Giovanni