For me, the crash is entirely unrelated to pinch to zooming actions. Sorry for not mentioning that earlier.

What a neat method of getting stack traces btw! coredump list shows that qutebrowser/Qt segfaults. See below for the full stack trace.

Should I open a new issue? Or should I ask the Qt people for help?

(gdb) bt
#0  __pthread_kill_implementation
    (threadid=<optimized out>, signo=signo@entry=11, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007fbc6109f2d3 in __pthread_kill_internal (signo=11, threadid=<optimized out>)
    at pthread_kill.c:78
#2  0x00007fbc6104fa08 in __GI_raise (sig=11) at ../sysdeps/posix/raise.c:26
#3  0x00007fbc6104fab0 in <signal handler called> () at /usr/lib/libc.so.6
#4  0x00007fbc3f6c10fd in QXcbConnection::xi2HandleGestureSwipeEvent(void*) ()
    at /usr/lib/qt6/plugins/platforms/../../../libQt6XcbQpa.so.6
#5  0x00007fbc3f6b097c in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) ()
    at /usr/lib/qt6/plugins/platforms/../../../libQt6XcbQpa.so.6
#6  0x00007fbc3f6b892c in QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
    at /usr/lib/qt6/plugins/platforms/../../../libQt6XcbQpa.so.6
#7  0x00007fbc3f6cdf97 in  () at /usr/lib/qt6/plugins/platforms/../../../libQt6XcbQpa.so.6
#8  0x00007fbc5f910981 in g_main_dispatch (context=0x7fbc38000fc0) at ../glib/glib/gmain.c:3460
#9  g_main_context_dispatch (context=0x7fbc38000fc0) at ../glib/glib/gmain.c:4200
#10 0x00007fbc5f96db39 in g_main_context_iterate.isra.0
    (context=context@entry=0x7fbc38000fc0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/glib/gmain.c:4276
#11 0x00007fbc5f90e032 in g_main_context_iteration (context=0x7fbc38000fc0, may_block=1)
    at ../glib/glib/gmain.c:4343
#12 0x00007fbc5fd344d4 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
    () at /usr/lib/libQt6Core.so.6
#13 0x00007fbc5fb44cd3 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
    at /usr/lib/libQt6Core.so.6
#14 0x00007fbc5fb3e378 in QCoreApplication::exec() () at /usr/lib/libQt6Core.so.6
#15 0x00007fbc5c55c91e in meth_QApplication_exec(PyObject*, PyObject*)
    (sipSelf=<optimized out>, sipArgs=<optimized out>)
    at /usr/src/debug/pyqt6/PyQt6-6.5.0/build/QtWidgets/sipQtWidgetsQApplication.cpp:1283
#16 0x00007fbc61404aa8 in cfunction_call
    (func=0x7fbc3fa17d30, args=<optimized out>, kwargs=<optimized out>)
--Type <RET> for more, q to quit, c to continue without paging--
    at Objects/methodobject.c:553
#17 0x00007fbc613e53e4 in _PyObject_MakeTpCall
    (tstate=0x7fbc61797a38 <_PyRuntime+166328>, callable=0x7fbc3fa17d30, args=<optimized out>, nargs=0, keywords=0x0) at Objects/call.c:214
#18 0x00007fbc613efbcb in _PyEval_EvalFrameDefault
    (tstate=<optimized out>, frame=<optimized out>, throwflag=<optimized out>)
    at Python/ceval.c:4773
#19 0x00007fbc614a9f6a in _PyEval_EvalFrame
    (throwflag=0, frame=0x7fbc618dc020, tstate=0x7fbc61797a38 <_PyRuntime+166328>)
    at ./Include/internal/pycore_ceval.h:73
#20 _PyEval_Vector
    (tstate=tstate@entry=0x7fbc61797a38 <_PyRuntime+166328>, func=func@entry=0x7fbc60ef9f80, locals=locals@entry=0x7fbc60f1e980, args=args@entry=0x0, argcount=argcount@entry=0, kwnames=kwnames@entry=0x0) at Python/ceval.c:6438
#21 0x00007fbc614a997c in PyEval_EvalCode
    (co=0x5570b9d04bb0, globals=<optimized out>, locals=0x7fbc60f1e980) at Python/ceval.c:1154
#22 0x00007fbc614c86b3 in run_eval_code_obj
    (tstate=tstate@entry=0x7fbc61797a38 <_PyRuntime+166328>, co=co@entry=0x5570b9d04bb0, globals=globals@entry=0x7fbc60f1e980, locals=locals@entry=0x7fbc60f1e980) at Python/pythonrun.c:1714
#23 0x00007fbc614c43ba in run_mod
    (mod=mod@entry=0x5570b9dd5150, filename=filename@entry=0x7fbc60ecc530, globals=globals@entry=0x7fbc60f1e980, locals=locals@entry=0x7fbc60f1e980, flags=flags@entry=0x7ffdff8b2bd8, arena=arena@entry=0x7fbc60e477b0) at Python/pythonrun.c:1735
#24 0x00007fbc614dadd3 in pyrun_file
    (fp=fp@entry=0x5570b9d00470, filename=filename@entry=0x7fbc60ecc530, start=start@entry=257, globals=globals@entry=0x7fbc60f1e980, locals=locals@entry=0x7fbc60f1e980, closeit=closeit@entry=1, flags=0x7ffdff8b2bd8) at Python/pythonrun.c:1630
#25 0x00007fbc614d9ef4 in _PyRun_SimpleFileObject
    (fp=0x5570b9d00470, filename=0x7fbc60ecc530, closeit=1, flags=0x7ffdff8b2bd8)
    at Python/pythonrun.c:440
#26 0x00007fbc614d8de8 in _PyRun_AnyFileObject
    (fp=0x5570b9d00470, filename=0x7fbc60ecc530, closeit=1, flags=0x7ffdff8b2bd8)
    at Python/pythonrun.c:79
#27 0x00007fbc614d3722 in pymain_run_file_obj
    (skip_source_first_line=0, filename=0x7fbc60ecc530, program_name=0x7fbc60918760)
    at Modules/main.c:360
#28 pymain_run_file (config=0x7fbc6177da80 <_PyRuntime+59904>) at Modules/main.c:379
#29 pymain_run_python (exitcode=0x7ffdff8b2bd4) at Modules/main.c:601
#30 Py_RunMain () at Modules/main.c:680
#31 0x00007fbc6149bf6b in Py_BytesMain (argc=<optimized out>, argv=<optimized out>)
    at Modules/main.c:734
#32 0x00007fbc61039850 in __libc_start_call_main
    (main=main@entry=0x5570b7ec3120 <main>, argc=argc@entry=2, argv=argv@entry=0x7ffdff8b2e28)
    at ../sysdeps/nptl/libc_start_call_main.h:58
#33 0x00007fbc6103990a in __libc_start_main_impl
    (main=0x5570b7ec3120 <main>, argc=2, argv=0x7ffdff8b2e28, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffdff8b2e18) at ../csu/libc-start.c:360
#34 0x00005570b7ec3045 in _start ()

Originally posted by @rien333 in #7662 (comment)