Thanks for the patch. Mesa is been rebuild with this patch. Still crashing:

Thread 7 (Thread 0x7fff4189b700 (LWP 1745)):
#0  0x00007ffff271f6ad in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fffede4b9f6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffede4bb0c in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff303404f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff2fdd9ca in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff2e0b0f3 in QThread::exec() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff5de6406 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007ffff2e0fda8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#9  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 6 (Thread 0x7fffd0f55700 (LWP 1744)):
#0  0x00007ffff1ce915f in pthread_cond_wait@@GLIBC_2.3.2 () from
/lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007ffff786b2c4 in ?? () from
/usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007ffff786b309 in ?? () from
/usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#4  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 5 (Thread 0x7fffd2bb6700 (LWP 1742)):
#0  0x00007ffff271f6ad in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fffede4b9f6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffede4bb0c in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff303404f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff2fdd9ca in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff2e0b0f3 in QThread::exec() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff545d6a5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007ffff2e0fda8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#9  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 4 (Thread 0x7fffe0ed1700 (LWP 1741)):
#0  0x00007ffff271f6ad in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fffede4b9f6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffede4bb0c in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff303404f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff2fdd9ca in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff2e0b0f3 in QThread::exec() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff545d6a5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#7  0x00007ffff2e0fda8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#9  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 3 (Thread 0x7fffe1f0d700 (LWP 1733)):
#0  0x00007ffff271f6ad in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fffede4b9f6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fffede4bb0c in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff303404f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007ffff2fdd9ca in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff2e0b0f3 in QThread::exec() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007ffff7f4b6d5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007ffff2e0fda8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#9  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 2 (Thread 0x7fffe2b7a700 (LWP 1727)):
#0  0x00007ffff271f6ad in poll () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff67b3150 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007ffff67b4ee9 in xcb_wait_for_event () from
/usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fffe4490b69 in ?? () from
/usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4  0x00007ffff2e0fda8 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007ffff1ce3494 in start_thread () from
/lib/x86_64-linux-gnu/libpthread.so.0
#6  0x00007ffff2728aff in clone () from /lib/x86_64-linux-gnu/libc.so.6

Thread 1 (Thread 0x7ffff7e0a940 (LWP 1723)):
#0  0x00007fff4b70c22d in PUSH_RESET (bin=0, push=0x555555bef630) at
../../../../../src/gallium/drivers/nouveau/nv30/nv30_winsys.h:39
#1  nv30_validate_fb (nv30=0x555555fb42f0) at
../../../../../src/gallium/drivers/nouveau/nv30/nv30_state_validate.c:102
#2  0x00007fff4b70cb29 in nv30_state_validate (nv30=nv30@entry=0x555555fb42f0,
mask=mask@entry=10240, hwtnl=hwtnl@entry=true) at
../../../../../src/gallium/drivers/nouveau/nv30/nv30_state_validate.c:493
#3  0x00007fff4b700f05 in nv30_clear (pipe=0x555555fb42f0, buffers=5,
color=0x555555f834c4, depth=1, stencil=0) at
../../../../../src/gallium/drivers/nouveau/nv30/nv30_clear.c:61
#4  0x00007fff4b458771 in st_Clear (ctx=0x555555f81a10, mask=272) at
../../../src/mesa/state_tracker/st_cb_clear.c:481
#5  0x00007ffff5e1594a in QSGBatchRenderer::Renderer::renderBatches() () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#6  0x00007ffff5e1b215 in QSGBatchRenderer::Renderer::render() () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#7  0x00007ffff5e26b3f in QSGRenderer::renderScene(QSGBindable const&) () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#8  0x00007ffff5e5daa6 in QSGDefaultLayer::grab() () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#9  0x00007ffff5e5df55 in QSGDefaultLayer::updateTexture() () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#10 0x00007ffff5f6b556 in QQuickShaderEffectMaterial::updateTextures() const ()
from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#11 0x00007ffff5e273b7 in QSGRenderer::preprocess() () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#12 0x00007ffff5e26b0f in QSGRenderer::renderScene(QSGBindable const&) () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#13 0x00007ffff5e2720b in QSGRenderer::renderScene(unsigned int) () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#14 0x00007ffff5e36eae in QSGRenderContext::renderNextFrame(QSGRenderer*,
unsigned int) () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#15 0x00007ffff5e8076e in QQuickWindowPrivate::renderSceneGraph(QSize const&)
() from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#16 0x00007ffff5e4d9a5 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#17 0x00007ffff5e8b216 in QQuickWindow::event(QEvent*) () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#18 0x00007ffff38c2b8c in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#19 0x00007ffff38ca341 in QApplication::notify(QObject*, QEvent*) () from
/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#20 0x00007ffff2fdf9e0 in QCoreApplication::notifyInternal2(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#21 0x00007ffff333360e in QWindowPrivate::deliverUpdateRequest() () from
/usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#22 0x00007ffff3333b59 in QWindow::event(QEvent*) () from
/usr/lib/x86_64-linux-gnu/libQt5Gui.so.5
#23 0x00007ffff5e8b1b5 in QQuickWindow::event(QEvent*) () from
/usr/lib/x86_64-linux-gnu/libQt5Quick.so.5
#24 0x00007ffff38c2b8c in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#25 0x00007ffff38ca341 in QApplication::notify(QObject*, QEvent*) () from
/usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#26 0x00007ffff2fdf9e0 in QCoreApplication::notifyInternal2(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#27 0x00007ffff3032fee in QTimerInfoList::activateTimers() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#28 0x00007ffff3033511 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#29 0x00007fffede4b7f7 in g_main_context_dispatch () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fffede4ba60 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007fffede4bb0c in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
#32 0x00007ffff303404f in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#33 0x00007ffff2fdd9ca in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#34 0x00007ffff2fe613c in QCoreApplication::exec() () from
/usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#35 0x0000555555572daf in main (argc=<optimized out>, argv=<optimized out>) at
./shell/main.cpp:166