Linux: Crash in wxPython example with GTK3 due to a segmentation fault in XRenderCreatePicture

[dee42]

In the wxPython example compiled with GTK3, after applying the CEF patch from #452, there is a secondary crash as soon as the main loop starts up.

The logging and traceback is as follows:

[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Detaching after vfork from child process 8815]
[wxpython.py] CEF Python 66.0
[Detaching after fork from child process 8821]
[wxpython.py] Python 2.7.16 64bit
[wxpython.py] wxPython 4.0.6 gtk3 (phoenix) wxWidgets 3.0.5
[New Thread 0x7fffe8475700 (LWP 8822)]
[Detaching after fork from child process 8823]
[New Thread 0x7fffe7c74700 (LWP 8824)]
[New Thread 0x7fffe7473700 (LWP 8825)]
[New Thread 0x7fffe6c72700 (LWP 8826)]
[New Thread 0x7fffe6471700 (LWP 8827)]
[New Thread 0x7fffe5c70700 (LWP 8828)]
[New Thread 0x7fffe546f700 (LWP 8829)]
[New Thread 0x7fffe4c6e700 (LWP 8830)]
[New Thread 0x7fffc7fff700 (LWP 8831)]
[New Thread 0x7fffc77fe700 (LWP 8832)]
[New Thread 0x7fffc6ffd700 (LWP 8833)]
[New Thread 0x7fffc67fc700 (LWP 8834)]
[New Thread 0x7fffc5ffb700 (LWP 8835)]
[New Thread 0x7fffc57fa700 (LWP 8836)]
[New Thread 0x7fffc4ff9700 (LWP 8837)]
[Detaching after fork from child process 8838]
[New Thread 0x7fff9fd56700 (LWP 8839)]
[0819/112542.762332:ERROR:sandbox_linux.cc(379)] InitializeSandbox() called with multiple threads in process gpu-process.
[New Thread 0x7fff9f555700 (LWP 8849)]
[New Thread 0x7fff9ed54700 (LWP 8850)]
[New Thread 0x7fff9e553700 (LWP 8851)]
[New Thread 0x7fff9dd52700 (LWP 8852)]

DevTools listening on ws://127.0.0.1:54417/devtools/browser/4bc7fd08-f299-46ae-8cc7-036b160ef36f
[New Thread 0x7fff9d286700 (LWP 8853)]
[New Thread 0x7fff9ca3f700 (LWP 8854)]
[wxpython.py] wx.GetDisplayPPI = (96, 96)
[wxpython.py] wx.GetDisplaySize = (3840, 1080)
[wxpython.py] MainFrame declared size: (900, 640)
[wxpython.py] MainFrame DPI scaled size: (900, 640)
[wxpython.py] MainFrame actual size: (900, 640)
[New Thread 0x7fff73d19700 (LWP 8855)]
[New Thread 0x7fff73518700 (LWP 8856)]
[0819/112543.136222:ERROR:gl_surface_glx.cc(581)] XGetWindowAttributes failed for window 67108866.
[0819/112543.136270:ERROR:gles2_command_buffer_stub.cc(226)] ContextResult::kFatalFailure: Failed to create surface.
[0819/112543.139327:ERROR:gpu_process_transport_factory.cc(1017)] Lost UI shared context.
[0819/112543.139957:ERROR:software_output_device_x11.cc(25)] XGetWindowAttributes failed for window 67108866

Thread 1 "python2.7" received signal SIGSEGV, Segmentation fault.
0x00007ffff35242e1 in XRenderCreatePicture () from /usr/lib/libXrender.so.1
(gdb) bt
#0  0x00007ffff35242e1 in XRenderCreatePicture () at /usr/lib/libXrender.so.1
#1  0x00007fffef81b298 in EndPaint() () at ../../components/viz/service/display_embedder/software_output_device_x11.cc:86
#2  0x00007fffef7e2840 in FinishDrawingFrame() () at ../../components/viz/service/display/software_renderer.cc:66
#3  0x00007fffef7b8831 in DrawFrame() () at ../../components/viz/service/display/direct_renderer.cc:332
#4  0x00007fffef7bc402 in DrawAndSwap() () at ../../components/viz/service/display/display.cc:356
#5  0x00007fffef7be49e in DrawAndSwap () at ../../components/viz/service/display/display_scheduler.cc:213
#6  0x00007fffef7be49e in AttemptDrawAndSwap() () at ../../components/viz/service/display/display_scheduler.cc:487
#7  0x00007fffef7bdcda in OnBeginFrameDeadline() () at ../../components/viz/service/display/display_scheduler.cc:503
#8  0x00007fffee7b6a0d in Run () at ../../base/callback.h:95
#9  0x00007fffee7b6a0d in RunTask() () at ../../base/debug/task_annotator.cc:61
#10 0x00007fffee7d2c6b in RunTask() () at ../../base/message_loop/message_loop.cc:395
#11 0x00007fffee7d32b5 in DeferOrRunPendingTask () at ../../base/message_loop/message_loop.cc:407
#12 0x00007fffee7d32b5 in DoWork() () at ../../base/message_loop/message_loop.cc:451
#13 0x00007fffee7d444d in base::MessagePumpGlib::Run(base::MessagePump::Delegate*) () at ../../base/message_loop/message_pump_glib.cc:309
#14 0x00007fffee7f2788 in Run () at ../../base/run_loop.cc:133
#15 0x00007fffee7f2788 in RunUntilIdle() () at ../../base/run_loop.cc:146
#16 0x00007fffee6596bf in CefBrowserMessageLoop::DoMessageLoopIteration() () at ../../cef/libcef/browser/browser_message_loop.cc:116
#17 0x00007fffea5d66a8 in __pyx_pw_14cefpython_py27_35MessageLoopWork(_object*, _object*) [clone .lto_priv.278] ()
    at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/cefpython3/cefpython_py27.so
#18 0x00007ffff7ebba8d in call_function (oparg=<optimized out>, pp_stack=0x7fffffffbef0) at Python/ceval.c:4360
#19 0x00007ffff7ebba8d in PyEval_EvalFrameEx (f=f@entry=0x7fffe9c22208, throwflag=throwflag@entry=0) at Python/ceval.c:3013
#20 0x00007ffff7ebe278 in PyEval_EvalCodeEx
    (co=<optimized out>, globals=<optimized out>, locals=locals@entry=0x0, args=args@entry=0x7ffff6ed1800, argcount=<optimized out>, kws=kws@entry=0x0, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:3608
#21 0x00007ffff7e3a07b in function_call (func=0x7ffff2a828c0, arg=0x7ffff6ed17e8, kw=0x0) at Objects/funcobject.c:523
#22 0x00007ffff7e0d4a3 in PyObject_Call (func=func@entry=0x7ffff2a828c0, arg=arg@entry=0x7ffff6ed17e8, kw=kw@entry=0x0) at Objects/abstract.c:2544
#23 0x00007ffff7e1c4cc in instancemethod_call (func=0x7ffff2a828c0, arg=0x7ffff6ed17e8, kw=0x0) at Objects/classobject.c:2600

#24 0x00007ffff7e0d4a3 in PyObject_Call (func=func@entry=0x7ffff2b23910, arg=arg@entry=0x7ffff2a84290, kw=0x0) at Objects/abstract.c:2544
#25 0x00007ffff7eb3d68 in PyEval_CallObjectWithKeywords (func=func@entry=0x7ffff2b23910, arg=arg@entry=0x7ffff2a84290, kw=kw@entry=0x0) at Python/ceval.c:4245
#26 0x00007ffff62ab357 in wxPyCallback::EventThunker(wxEvent&) (this=<optimized out>, event=...) at ../../../../sip/cpp/sip_corewxEvtHandler.cpp:71
#27 0x00007ffff569906e in wxEvtHandler::ProcessEventIfMatchesId(wxEventTableEntryBase const&, wxEvtHandler*, wxEvent&) ()
    at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#28 0x00007ffff56993ea in wxEvtHandler::SearchDynamicEventTable(wxEvent&) () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#29 0x00007ffff5699480 in wxEvtHandler::TryHereOnly(wxEvent&) () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#30 0x00007ffff5699533 in wxEvtHandler::ProcessEventLocally(wxEvent&) () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#31 0x00007ffff56995d1 in wxEvtHandler::ProcessEvent(wxEvent&) () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#32 0x00007ffff64cf693 in sipwxPyApp::ProcessEvent(wxEvent&) (this=0x555555bd9080, event=...) at ../../../../sip/cpp/sip_corewxPyApp.cpp:660
#33 0x00007ffff5699367 in wxEvtHandler::SafelyProcessEvent(wxEvent&) () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#34 0x00007ffff55f3cd0 in wxTimerImpl::SendEvent() () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#35 0x00007ffff65f0290 in sipwxTimer::Notify() (this=0x555556072ee0) at ../../../../sip/cpp/sip_corewxTimer.cpp:115
#36 0x00007ffff5a4a2b2 in timeout_callback () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_gtk3u_core-3.0.so.0
#37 0x00007ffff44ce3c4 in  () at /usr/lib/libglib-2.0.so.0
#38 0x00007ffff44cebb0 in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#39 0x00007ffff44d0b11 in  () at /usr/lib/libglib-2.0.so.0
#40 0x00007ffff44d1a63 in g_main_loop_run () at /usr/lib/libglib-2.0.so.0
#41 0x00007ffff4dd6eef in gtk_main () at /usr/lib/libgtk-3.so.0
#42 0x00007ffff5a38455 in wxGUIEventLoop::DoRun() () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_gtk3u_core-3.0.so.0
#43 0x00007ffff554608d in wxEventLoopBase::Run() () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#44 0x00007ffff55096b6 in wxAppConsoleBase::MainLoop() () at /home/deem/j5-environments/28.0/python/lib/python2.7/site-packages/wx/libwx_baseu-3.0.so.0
#45 0x00007ffff64d4741 in wxPyApp::MainLoop() (this=0x555555bd9080) at ../../../../sip/cpp/sip_corewxPyApp.cpp:316
--Type <RET> for more, q to quit, c to continue without paging--
#46 0x00007ffff64d4957 in meth_wxPyApp_MainLoop(PyObject*, PyObject*) (sipSelf=<optimized out>, sipArgs=<optimized out>) at ../../../../sip/cpp/sip_corewxPyApp.cpp:1837
#47 0x00007ffff7ebc42f in call_function (oparg=<optimized out>, pp_stack=0x7fffffffc8b0) at Python/ceval.c:4376
#48 0x00007ffff7ebc42f in PyEval_EvalFrameEx (f=f@entry=0x7fffe9c23210, throwflag=throwflag@entry=0) at Python/ceval.c:3013
#49 0x00007ffff7ebda3d in fast_function (nk=<optimized out>, na=<optimized out>, n=1, pp_stack=0x7fffffffc9c0, func=0x7ffff2b28668) at Python/ceval.c:4461
#50 0x00007ffff7ebda3d in call_function (oparg=<optimized out>, pp_stack=0x7fffffffc9c0) at Python/ceval.c:4396
#51 0x00007ffff7ebda3d in PyEval_EvalFrameEx (f=f@entry=0x7ffff6d2ecc8, throwflag=throwflag@entry=0) at Python/ceval.c:3013
#52 0x00007ffff7ebda3d in fast_function (nk=<optimized out>, na=<optimized out>, n=0, pp_stack=0x7fffffffcad0, func=0x7ffff2a82050) at Python/ceval.c:4461
#53 0x00007ffff7ebda3d in call_function (oparg=<optimized out>, pp_stack=0x7fffffffcad0) at Python/ceval.c:4396
#54 0x00007ffff7ebda3d in PyEval_EvalFrameEx (f=f@entry=0x7ffff6d2e938, throwflag=throwflag@entry=0) at Python/ceval.c:3013
#55 0x00007ffff7ebe278 in PyEval_EvalCodeEx
    (co=co@entry=0x7ffff7591a30, globals=globals@entry=0x7ffff7a11168, locals=locals@entry=0x7ffff7a11168, args=args@entry=0x0, argcount=argcount@entry=0, kws=kws@entry=0x0, kwcount=0, defs=0x0, defcount=0, closure=0x0) at Python/ceval.c:3608
#56 0x00007ffff7ebe429 in PyEval_EvalCode (co=co@entry=0x7ffff7591a30, globals=globals@entry=0x7ffff7a11168, locals=locals@entry=0x7ffff7a11168) at Python/ceval.c:669
#57 0x00007ffff7ee3dd9 in run_mod
    (arena=0x555555b8c840, flags=0x7fffffffcd1c, locals=0x7ffff7a11168, globals=0x7ffff7a11168, filename=0x7ffff7591a30 "\002", mod=0x555555bdd2d0)
    at Python/pythonrun.c:1385
#58 0x00007ffff7ee3dd9 in PyRun_FileExFlags
    (fp=fp@entry=0x55555558d5a0, filename=filename@entry=0x7fffffffd361 "wxpython.py", start=start@entry=257, globals=globals@entry=0x7ffff7a11168, locals=locals@entry=0x7ffff7a11168, closeit=closeit@entry=1, flags=0x7fffffffcd1c) at Python/pythonrun.c:1371
#59 0x00007ffff7ee526c in PyRun_SimpleFileExFlags
    (fp=fp@entry=0x55555558d5a0, filename=0x7fffffffd361 "wxpython.py", closeit=closeit@entry=1, flags=flags@entry=0x7fffffffcd1c) at Python/pythonrun.c:957
#60 0x00007ffff7ee593c in PyRun_AnyFileExFlags (fp=fp@entry=0x55555558d5a0, filename=<optimized out>, closeit=closeit@entry=1, flags=flags@entry=0x7fffffffcd1c)
    at Python/pythonrun.c:761
#61 0x00007ffff7ef9237 in Py_Main (argc=<optimized out>, argv=<optimized out>) at Modules/main.c:641
#62 0x00007ffff7a65ee3 in __libc_start_main () at /usr/lib/libc.so.6
#63 0x000055555555507e in _start ()

[cztomczak]

To support GTK 3 you need to build CEF with GTK 3 enabled, this can be done with the automate.py script by providing --use-gtk3 flag. Also you need to patch cefpython sources with the patch that is attached in one of the comments in Issue #446.

After following the instructions above and if the issue still persists answer these two questions:

1. Do you use any custom window settings in OS that e.g. forces transparency on windows?
2. Does disabling GPU by passing --disable-gpu and disable-gpu-compositing switches make any difference?

[dee42]

Hi, thanks for this information. I recompiled with --with-gtk3 (I didn't clean, but since it rebuilt everything where the Makefile was touched this seemed unnecessary). I applied the patch from #446. I disabled compositing on my Window Manager. I passed in the disable-gpu and disable-gpu-compositing switches to cef Initialize in the wxpython example. Exact same segmentation fault and traceback.

[cztomczak]

What GTK 3 version is installed in your OS? Can you try installing version <= 3.14? Versions >= 3.15 are known to have issues with CEF (see this comment https://github.com/cztomczak/cefcapi/issues/9#issuecomment-348821478).

[dee42]

Unfortunately I need to work off a base of Ubuntu 18.04, which comes with GTK 3.22. Do you have a patch that gets it to work without transparency? Reading your comment, I can see that was the blocker, but I do not need transparency.

[cztomczak]

The referenced issue reports that CEF has issues with GTK 3.22 default visual in general. You can try changing the visual, there is C code available there. I can't say if that will help you resolve the issue here, but it's worth a try.

[dee42]

Thanks. I have fixed the issue for me by installing wxPython wheels linked to GTK2. The standard pip install ends up linked to GTK3. The wheels are available here: https://extras.wxpython.org/wxPython4/extras/linux/gtk2/ubuntu-18.04. I'm going to stop looking into this now, as that's a good enough solution for me, and it looks like next version of cefpython, when it is released, will have full GTK3 support.

[cztomczak]

Duplicate of #447.