adjusted traceback:

Thread 1 "gnome-terminal-" received signal SIGSEGV, Segmentation fault.
_gdk_wayland_shm_surface_get_wl_buffer (surface=<optimized out>) at gdkdisplay-wayland.c:1410
1410      return data->buffer;
(gdb) bt
#0  _gdk_wayland_shm_surface_get_wl_buffer (surface=<optimized out>) at gdkdisplay-wayland.c:1410
#1  0x00007f4144a1097c in gdk_wayland_window_ensure_cairo_surface (window=<optimized out>)
    at gdkwindow-wayland.c:889
#2  0x00007f4144a109ad in gdk_window_impl_wayland_begin_paint (window=<optimized out>) at gdkwindow-wayland.c:928
#3  0x00007f41449c4f7e in gdk_window_begin_paint_internal (region=0x555d37ddc0a0, window=0x555d3802d2a0)
    at gdkwindow.c:2954
#4  gdk_window_begin_paint_internal (window=0x555d3802d2a0, region=0x555d37ddc0a0) at gdkwindow.c:2930
#5  0x00007f41449c54fe in gdk_window_begin_draw_frame (window=window@entry=0x555d3802d2a0, 
    region=region@entry=0x555d37ddc0a0) at gdkwindow.c:3257
#6  0x00007f4144e15cbb in gtk_widget_render (widget=widget@entry=0x555d37734720, window=0x555d3802d2a0, 
    region=0x555d37ddc0a0) at gtkwidget.c:17587
#7  0x00007f4144cbf2b9 in gtk_main_do_event (event=0x7fffb927e0a0) at gtkmain.c:1840
#8  gtk_main_do_event (event=<optimized out>) at gtkmain.c:1687
#9  0x00007f41449a7f79 in _gdk_event_emit (event=event@entry=0x7fffb927e0a0) at gdkevents.c:73
#10 0x00007f41449b9291 in _gdk_window_process_updates_recurse_helper (window=0x555d3802d2a0, 
    expose_region=<optimized out>) at gdkwindow.c:3874
#11 0x00007f41449ba465 in gdk_window_process_updates_internal (window=0x555d3802d2a0) at gdkwindow.c:4020
#12 0x00007f41449ba624 in gdk_window_process_updates_with_mode (recurse_mode=<optimized out>, 
    window=<optimized out>) at gdkwindow.c:4215
#13 gdk_window_process_updates_with_mode (window=<optimized out>, recurse_mode=<optimized out>)
    at gdkwindow.c:4186
#14 0x00007f41446bb996 in _g_closure_invoke_va (closure=0x555d37fb6700, return_value=0x0, 
    instance=0x555d376fbf90, args=0x7fffb927e3e0, n_params=0, param_types=0x0) at ../gobject/gclosure.c:873
#15 0x00007f41446d8228 in g_signal_emit_valist (instance=0x555d376fbf90, signal_id=<optimized out>, detail=0, 
    var_args=var_args@entry=0x7fffb927e3e0) at ../gobject/gsignal.c:3306
#16 0x00007f41446d89d3 in g_signal_emit (instance=instance@entry=0x555d376fbf90, signal_id=<optimized out>, 
    detail=detail@entry=0) at ../gobject/gsignal.c:3453
#17 0x00007f41449b1383 in _gdk_frame_clock_emit_paint (frame_clock=frame_clock@entry=0x555d376fbf90)
    at gdkframeclock.c:643
#18 0x00007f41449b1cc3 in gdk_frame_clock_paint_idle (data=0x555d376fbf90) at gdkframeclockidle.c:450
#19 0x00007f414499bf3d in gdk_threads_dispatch (data=data@entry=0x555d378c0ee0) at gdk.c:777
#20 0x00007f41445d2021 in g_timeout_dispatch (source=source@entry=0x555d383029c0, 
    callback=0x7f414499bf10 <gdk_threads_dispatch>, user_data=0x555d378c0ee0) at ../glib/gmain.c:4668
#21 0x00007f41445d1510 in g_main_dispatch (context=0x555d376f8350) at ../glib/gmain.c:3179
#22 g_main_context_dispatch (context=context@entry=0x555d376f8350) at ../glib/gmain.c:3844
#23 0x00007f41445d18a0 in g_main_context_iterate (context=context@entry=0x555d376f8350, block=block@entry=1, 
    dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:3917
#24 0x00007f41445d1943 in g_main_context_iteration (context=context@entry=0x555d376f8350, 
    may_block=may_block@entry=1) at ../glib/gmain.c:3978
#25 0x00007f41447e4d55 in g_application_run (application=0x555d379c20f0, argc=<optimized out>, 
    argv=<optimized out>) at ../gio/gapplication.c:2559
#26 0x0000555d365bb0c2 in main (argc=<optimized out>, argv=<optimized out>) at server.c:187

This is due to the PS0 setting.

Removing upstream link, this is fedora-specific in our added patches. And it probably is on the gnome-terminal side, not the vte side.

Fix (interdiff, can make a separate diff as well):

diff --git a/gnome-terminal-cntr-ntfy-autottl-ts.patch b/gnome-terminal-cntr-ntfy-autottl-ts.patch
index 1180fc9..21af98d 100644
--- a/gnome-terminal-cntr-ntfy-autottl-ts.patch
+++ b/gnome-terminal-cntr-ntfy-autottl-ts.patch
@@ -5597,7 +5597,7 @@ index 9c9b29f48c83..4d6d057f7fda 100644
    gboolean user_title; /* title was manually set */
    GSList *match_tags;
    guint contents_changed_source_id;
-@@ -886,6 +888,15 @@ terminal_screen_format_title (TerminalScreen *screen,
+@@ -886,6 +888,17 @@ terminal_screen_format_title (TerminalScreen *screen,
        add_sep = FALSE;
      }
  
@@ -5608,6 +5608,8 @@ index 9c9b29f48c83..4d6d057f7fda 100644
 +      priv->current_cmdline[0] != '\0')
 +    {
 +      g_string_append_printf (title, " — %s", priv->current_cmdline);
++      if (title->len > 1024)
++        g_string_set_size (title, 1024);
 +    }
 +
    if (*titleptr == NULL || strcmp (title->str, *titleptr) != 0)

1024 per suggestion from @chpe (it's the maximum title length VTE sets itself for things.)

-> https://src.fedoraproject.org/rpms/gnome-terminal/pull-request/2

Reproducer:

mkdir ~/crash-pad
cd ~/crash-pad
for foo in $(seq 1 20000) ; do touch this-is-a-really-long-filename:-so-long-i-just-need-to-fill-space-blah-blah-blah-$foo ; done
grep "test string" *

++      if (title->len > 1024)
++        g_string_set_size (title, 1024);

This could truncate a UTF-8 character in the middle, making title->str contain invalid UTF-8.

(In reply to Christian Persch from comment #7)
> ++      if (title->len > 1024)
> ++        g_string_set_size (title, 1024);
> 
> This could truncate a UTF-8 character in the middle, making title->str
> contain invalid UTF-8.

g_utf8_substring might be a better choice?

(In reply to Debarshi Ray from comment #8)
> (In reply to Christian Persch from comment #7)
> > ++      if (title->len > 1024)
> > ++        g_string_set_size (title, 1024);
> > 
> > This could truncate a UTF-8 character in the middle, making title->str
> > contain invalid UTF-8.
> 
> g_utf8_substring might be a better choice?

That's one option, yes.

(BTW, there's another problem in that priv->current_cmdline is used here in the title, and also the notification body text, but it is just slurped from /proc/$pid/cmdline and never validated as UTF-8!)

By the way, I'd like to point out that there's the hidden show-foreground-process-in-title option to disable the title updates to work around this bug.

It's not exposed in the graphical user interface, but if you go to /org/gnome/terminal/legacy/profiles: in dconf-editor and select your gnome-terminal profile, you will see it.

We were debugging this together on IRC, and here's my summary:

1. The test from comment 6 creates a PS0 that is about 1,729,000 characters long (it depends on your hostname!).
2. That is almost 2^21 characters - remember that number for later.
2. That string is then set on the title Label in a TerminalHeaderbar
3. That label is properly set to ellipsize.
4. When the label is measured, it creates a PangoLayout with that given text and tells Pango to measure it
5. Pango does integer measurements in Pango units (1 pixel = 2^10 Pango Units)
6. Glyphs are almost 16 pixels wide, that is about 2^4 pixels.
7. Pango now has to deal with sizes going up to 2^(10 + 4 + 21) = 2^35.
8. Pango's API reports sizes as ints (and I suppose uses ints internally), so at most 2^31.

=> The numbers Pango reports for strings like this are completely busted.

9. Pango returns a random number that overflowed multiples times to the label (from step 4).
10. Sometimes that number is very large. In my current test, it is 128779.
11. GTK's sizing machinery deals with that fine.
12. GtkWindow resizes itself to the required size.
13. Wayland deals with it fine.
14. When it comes time to paint the window, we prepare to draw.
15. We do that by creating a cairo surface for the Window's size.
16. Cairo conforms to X11 limits and does not allow sizes larger 1985's int (today's int16): 2^15.

=> Cairo explodes because 128779 is larger than 32767.

=> GTK can't deal with Cairo complaining and crashes.

And that's where we are.

While the real problems are the ones I've outlined with the "=>", those are really hard to fix.

So the best fix is probably to just cut the PS0 string to some reasoanbly large number that doesn't overflow Pango and let it be properly ellipsized. The upper bound would be 2^(31 - 10 - 4) = 2^(17) = 131,072, but I don't think anybody can read more than 1,000 characters, even with a really small font and a 4k monitor.  
So I'd pick a number that is far enough away from either (1000 < number < 131072) and cut the string there.

That was fun to debug.

(In reply to Christian Persch from comment #9)
> (In reply to Debarshi Ray from comment #8)
> > (In reply to Christian Persch from comment #7)
> > > ++      if (title->len > 1024)
> > > ++        g_string_set_size (title, 1024);
> > > 
> > > This could truncate a UTF-8 character in the middle, making title->str
> > > contain invalid UTF-8.
> > 
> > g_utf8_substring might be a better choice?
> 
> That's one option, yes.

After debugging with Benjamin (see comment 11), I am thinking that vanilla gnome-terminal should always suitably truncate the window title. Crashes like this aren't something that can only be caused by the window title automatically reflecting the current command. One could do the same by emitting the OSC 0 escape sequence with a really long string.

> (BTW, there's another problem in that priv->current_cmdline is used here in
> the title, and also the notification body text, but it is just slurped from
> /proc/$pid/cmdline and never validated as UTF-8!)

I threw g_utf8_make_valid() at it to enforce valid UTF-8.

Built gnome-terminal-3.34.2-2.fc31:
https://bodhi.fedoraproject.org/updates/FEDORA-2020-3059e6f8a8

Also fixed in Rawhide.

I will do a build for Fedora 32 later once the currently pending GNOME 3.35.92 mega-update makes its way into stable.

Thanks for the detailed bug report and sample fixes, Bill. In the end I tweaked your patch a bit, as we discussed above.

gnome-terminal-3.34.2-2.fc31 has been pushed to the Fedora 31 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2020-3059e6f8a8

gnome-terminal-3.34.2-2.fc31 has been pushed to the Fedora 31 stable repository. If problems still persist, please make note of it in this bug report.