Something related to the wxScintilla control, because I see something here:
wxSCIListBoxWin::OnSize(wxSizeEvent&)
That looks llke the same error I fixed in rev 13473. It's caused by gtk3 issuing an OnSize() event that the original author (of our version of wxScintilla) did not expect.
The original author does not delete the codecompletion suggestion windows, but posts them to wxPendingDelete() queue instead. So there's no telling when the window(s) get deleted. Documentation says wxPendingDelete queue is run on the next available time. Who knows. I suspect either onIdle() or onYield(). Very dangerous. God-only-knows when the windows get freed.
The OnSize() code attempts to ask the ListWindow for an icon width, but the window evidently has already been freed.
The fix in cb rev 13473 cached the icon size so subsequent access to the window(s) pointer was no longer necessary.
The OP will need to update to at least rev 13473 to avoid this crash.
Edit: or maybe use one of the Linux's build for the nightly build.
https://forums.codeblocks.org/index.php/board,20.0.html