Help with locate a bug, maybe related to libproxy

[Martin]

Dear libproxy maintainers, dear Laurent, dear Jeremy, dear Iain,

recently, the new version 1.6.0 of the Python based Jabber client Gajim
has been released. Unfortunately, it crashes (only) on Debian.

This backtrace
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1028192#10
seems to point to libproxy as the culprit.

AFAIK, libproxy is now in the dependency chain, because Gajim migrated
to libsoup3.

Neither Gajim upstream nor others could make sense of the crash, so far.

Any idea, what is going on?

TIA & Cheers