Segmentation Fault (SIGSEGV) on all glX* Calls in Xenial with Mesa Drivers

ted dr

Setup is:

OS: Xenial (Ubuntu 16.04.6) on VMWare (Tried with VirtualBox, too)
Graphics: Mesa Drivers
Qt: Tried 5.12.6, 5.13.1 and 5.14.1

Symptoms:

Source code compiles OK.
Qt own examples works fine. But again, my source code works fine on all other setups.
Binary runs on other Ubuntu versions (tried 19.10 & 18.04)
Binary runs on Xenial (16.04) if installed on host and Nvidia or Intel drivers are present.
Binary results in segmentation fault if it's defined as QApplication! Fault occurs on glXQueryExtensionStrings in libGL.so.1
(specifically on MenuBar class). Also all other glX* calls result in segmentation fault.
- Even tried a simple glX* program from scratch. Until QApplication constructor is not called, everything works fine.

Workaround:

Problem seemed to be in OpenGL Extensions.
All Xcb dependencies were reinstalled but to no avail.
I compiled Qt 5.12 from source and it worked!
1 by 1 comparison in libraries with installable version lead me to something weird: if the $QT_HOME/gcc_64/plugins/platformthemes/libqgtk3.so was deleted, everything worked fine!

Reults:

Firstly I mentioned this problem here hoping that someone might find it useful and wouldn't waste this much time.
Secondly, I cannot figure out why this would fix the problem! could someone explain how this fixed segmentation fault error?

SGaist

Hi,

What desktop environment are you using ?
Did you check with ldd if all the dependencies for that plugin are properly found ?

ted dr

@SGaist Hi,

Default Ubuntu 16.4.06 (Xenial) on VMWare Workstation:
- "apt-cache show gnome-shell | grep Version" yields: Version: 3.18.5-0ubuntu0.3
- "unity --version" yields: unity 7.4.5
- "lightdm --version" yields: lightdm 1.18.3
- "Graphics" : SVGA3D; build: RELEASE; LLVM; (Note: I tried this for Oracle VirtualBox, too)
ldd on "libqgtk3.so" nothing is suspicious:
linux-vdso.so.1 => (0x00007ffe04b8e000)
libQt5DBus.so.5 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libQt5DBus.so.5 (0x00007fa785be2000)
libQt5Gui.so.5 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libQt5Gui.so.5 (0x00007fa785395000)
libQt5Core.so.5 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libQt5Core.so.5 (0x00007fa784bfa000)
libGL.so.1 => /usr/lib/x86_64-linux-gnu/libGL.so.1 (0x00007fa784986000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa784769000)
libgtk-3.so.0 => /usr/lib/x86_64-linux-gnu/libgtk-3.so.0 (0x00007fa783e3a000)
libgdk-3.so.0 => /usr/lib/x86_64-linux-gnu/libgdk-3.so.0 (0x00007fa783b5f000)
libatk-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libatk-1.0.so.0 (0x00007fa78393a000)
libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007fa7835b2000)
libpangocairo-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007fa7833a5000)
libgdk_pixbuf-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007fa783183000)
libcairo-gobject.so.2 => /usr/lib/x86_64-linux-gnu/libcairo-gobject.so.2 (0x00007fa782f7a000)
libpango-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007fa782d2e000)
libcairo.so.2 => /usr/lib/x86_64-linux-gnu/libcairo.so.2 (0x00007fa782a1a000)
libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007fa7827c7000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fa7824b6000)
libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007fa7822a4000)
libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fa781f6a000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fa781b87000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fa78187e000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa781666000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa78129c000)
libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007fa781050000)
libz.so.1 => /home/ted/src/grpc/lib/libz.so.1 (0x00007fa780e34000)
libicui18n.so.56 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libicui18n.so.56 (0x00007fa78099b000)
libicuuc.so.56 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libicuuc.so.56 (0x00007fa7805e3000)
libicudata.so.56 => /opt/Qt5.12.6/5.12.6/gcc_64/plugins/platformthemes/./../../lib/libicudata.so.56 (0x00007fa77ec00000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa77e9fc000)
libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fa77e7fa000)
/lib64/ld-linux-x86-64.so.2 (0x00007fa7860c2000)
libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007fa77e5d1000)
libxcb-dri3.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri3.so.0 (0x00007fa77e3ce000)
libxcb-present.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-present.so.0 (0x00007fa77e1cb000)
libxcb-sync.so.1 => /usr/lib/x86_64-linux-gnu/libxcb-sync.so.1 (0x00007fa77dfc4000)
libxshmfence.so.1 => /usr/lib/x86_64-linux-gnu/libxshmfence.so.1 (0x00007fa77ddc1000)
libglapi.so.0 => /usr/lib/x86_64-linux-gnu/libglapi.so.0 (0x00007fa77db90000)
libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007fa77d98d000)
libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007fa77d787000)
libX11-xcb.so.1 => /usr/lib/x86_64-linux-gnu/libX11-xcb.so.1 (0x00007fa77d585000)
libxcb-glx.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-glx.so.0 (0x00007fa77d36c000)
libxcb-dri2.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-dri2.so.0 (0x00007fa77d167000)
libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fa77cf45000)
libXxf86vm.so.1 => /usr/lib/x86_64-linux-gnu/libXxf86vm.so.1 (0x00007fa77cd3f000)
libdrm.so.2 => /usr/lib/x86_64-linux-gnu/libdrm.so.2 (0x00007fa77cb2e000)
libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007fa77c92a000)
libXi.so.6 => /usr/lib/x86_64-linux-gnu/libXi.so.6 (0x00007fa77c71a000)
libatk-bridge-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0 (0x00007fa77c4eb000)
libepoxy.so.0 => /usr/lib/x86_64-linux-gnu/libepoxy.so.0 (0x00007fa77c1f6000)
libpangoft2-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007fa77bfe0000)
libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007fa77bd9d000)
libXinerama.so.1 => /usr/lib/x86_64-linux-gnu/libXinerama.so.1 (0x00007fa77bb9a000)
libXrandr.so.2 => /usr/lib/x86_64-linux-gnu/libXrandr.so.2 (0x00007fa77b98f000)
libXcursor.so.1 => /usr/lib/x86_64-linux-gnu/libXcursor.so.1 (0x00007fa77b785000)
libXcomposite.so.1 => /usr/lib/x86_64-linux-gnu/libXcomposite.so.1 (0x00007fa77b582000)
libxkbcommon.so.0 => /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007fa77b343000)
libwayland-cursor.so.0 => /usr/lib/x86_64-linux-gnu/libwayland-cursor.so.0 (0x00007fa77b13b000)
libwayland-egl.so.1 => /usr/lib/x86_64-linux-gnu/libwayland-egl.so.1 (0x00007fa77af39000)
libwayland-client.so.0 => /usr/lib/x86_64-linux-gnu/libwayland-client.so.0 (0x00007fa77ad2a000)
libmirclient.so.9 => /usr/lib/x86_64-linux-gnu/libmirclient.so.9 (0x00007fa77aa83000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fa77a87b000)
libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007fa77a659000)
libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007fa77a43e000)
libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007fa77a194000)
libthai.so.0 => /usr/lib/x86_64-linux-gnu/libthai.so.0 (0x00007fa779f8b000)
libpixman-1.so.0 => /usr/lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007fa779ce3000)
libpng12.so.0 => /lib/x86_64-linux-gnu/libpng12.so.0 (0x00007fa779abe000)
libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fa7798ba000)
libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fa7796b0000)
libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007fa7794a6000)
libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007fa77929e000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fa77902e000)
libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007fa786224000)
libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fa778e2a000)
libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fa778c24000)
libatspi.so.0 => /usr/lib/x86_64-linux-gnu/libatspi.so.0 (0x00007fa7789f5000)
libharfbuzz.so.0 => /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007fa778797000)
libmircommon.so.7 => /usr/lib/x86_64-linux-gnu/libmircommon.so.7 (0x00007fa778550000)
libmirprotobuf.so.3 => /usr/lib/x86_64-linux-gnu/libmirprotobuf.so.3 (0x00007fa7782de000)
libcapnp-0.5.3.so => /usr/lib/x86_64-linux-gnu/libcapnp-0.5.3.so (0x00007fa778056000)
libmircore.so.1 => /usr/lib/x86_64-linux-gnu/libmircore.so.1 (0x00007fa777e4d000)
libboost_system.so.1.58.0 => /usr/lib/x86_64-linux-gnu/libboost_system.so.1.58.0 (0x00007fa777c49000)
libprotobuf-lite.so.9 => /usr/lib/x86_64-linux-gnu/libprotobuf-lite.so.9 (0x00007fa777a18000)
libdatrie.so.1 => /usr/lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007fa777810000)
liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fa7775ee000)
libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007fa77730d000)
libgraphite2.so.3 => /usr/lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007fa7770e7000)
libboost_filesystem.so.1.58.0 => /usr/lib/x86_64-linux-gnu/libboost_filesystem.so.1.58.0 (0x00007fa776ecf000)
libkj-0.5.3.so => /usr/lib/x86_64-linux-gnu/libkj-0.5.3.so (0x00007fa776ca6000)
libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007fa776a92000)

SGaist

I see zlib which is not the one from your system that gets loaded.

What version of Qt is provided by your distribution ?

ted dr

@SGaist

Yes I bolded that one since that was the only thing that differed in my setup but I don't think that's the problem since everything else works with that custom compiled library :?
sudo apt policy qt5-default returns this:
Installed: (none)
Candidate: 5.5.1+dfsg-16ubuntu7.7
Version table:
5.5.1+dfsg-16ubuntu7.7 500

SGaist

Even if it's old, I would try with this version if Qt to see if you have the same issue going on.