Segfault immediately upon execution in Kubuntu 18.10

[RogueScholar]

Describe the bug
When clicking on Polo in the launcher or issuing polo-gtk command in the terminal, app fails to open. Terminal output reveals segmentation fault.

$ polo-gtk
[17:54:05.973] Architecture: 64-bit
[17:54:05.973] Host Name: Kubuntu
[17:54:05.973] CPU Cores: 4
[17:54:05.973] RAM: 7988 MB
[17:54:05.993] [Warning] Deleted invalid lock
(polo-gtk:8182): Pango-CRITICAL **: 17:54:06.671: pango_font_description_from_string: assertion 'str != NULL' failed
[17:54:09.041] MainWindow: save_session()
[1]    8182 segmentation fault (core dumped)  polo-gtk

System:

• Operating System: Kubuntu 18.10

• KDE Plasma Version: 5.15.3

• KDE Frameworks Version: 5.54.0

• Qt Version: 5.11.1

• Kernel Version: 4.20.0-15.1-liquorix-amd64

• OS Type: 64-bit

• Processors: 4 × Intel® Core™ i7-2620M CPU @ 2.70GHz

• Memory: 7.8 GiB of RAM

• Application Version: 18.8.3-176-ubuntu18.10.1

***I am a donating user with the polo-donation-plugins package installed as well.

[franznemeth]

Happens to me too on Fedora 30.
Once I delete polo-last-session.json polo starts again.

[zcsteele]

I ran into the same issue on Rhino linux 2023.4 (kernel version 6.7.1-060701-generic), but clearing the session file wasn't enough to fix the issue.

After a bit of debugging, I tracked the issue to the code that uses a regex to determine the version of 7-Zip installed. I have opened PR #284 to allow the regex to handle the newer formatting used by 7-Zip.