Comment # 7 on bug 1030828 from Dominique Leuenberger

(In reply to Fred Blaise from comment #6)
> Yes it does, again just 20s ago, after a fresh restart... and I am going to
> get it every 5mn doing nothing special.

Interesting - there are two GNOME releases difference (3.20 in Leap vs 3.24 in
TW)

Please extract a backtrace:

coredumpctl gdb gnome-shell

it will likely tell you to install missing debuginfo packagges - do so, to get
a useful trace

at the (gdb) prompt, type: thread apply all bt full

(eedinfo set - waiting for backtrace)