snapped app with qtwebengine fails to run

[Grzegorz Mazur]

I've tried to snap a simple Qt application making use of QtWebEngine (see https://github.com/grzegorzmazur/qtwebengine_snap). Building the snap according to the documentation on snapping Qt applications seems to work well, but attempt to run the application produces:

Qt: Session management error: None of the authentication protocols specified are supported
libpng warning: iCCP: known incorrect sRGB profile
Could not find QtWebEngineProcess
Aborted (core dumped)

Manually setting

export QTWEBENGINEPROCESS_PATH=/snap/qtwebengine-snap/current/usr/lib/x86_64-linux-gnu/qt5/libexec/QtWebEngineProcess

results in

Qt: Session management error: None of the authentication protocols specified are supported
libpng warning: iCCP: known incorrect sRGB profile
Installed Qt WebEngine locales directory not found at location /usr/share/qt5/translations/qtwebengine_locales. Trying application directory...
Qt WebEngine locales directory not found at location /snap/qtwebengine-snap/x1/bin/qtwebengine_locales. Trying fallback directory... Translations MAY NOT not be correct.
Path override failed for key ui::DIR_LOCALES and path '/home/mazur/snap/qtwebengine-snap/x1/.qtwebengine_snap'
Qt WebEngine resources not found at /usr/share/qt5/resources. Trying parent directory...
Qt WebEngine resources not found at /usr/share/qt5. Trying application directory...
Qt WebEngine resources not found at /snap/qtwebengine-snap/x1/bin. Trying fallback directory... The application MAY NOT work.
[0711/152354.110396:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.qtwebengine_snap/qtwebengine_resources.pak
Some features may not be available.
[0711/152354.119717:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.qtwebengine_snap/qtwebengine_resources_100p.pak
Some features may not be available.
[0711/152354.119751:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.qtwebengine_snap/qtwebengine_resources_200p.pak
Some features may not be available.
[0711/152354.233507:WARNING:resource_bundle_qt.cpp(115)] locale_file_path.empty() for locale
[23311:23311:0711/152354.379528:FATAL:credentials.cc(155)] Check failed: NamespaceUtils::DenySetgroups(). : Permission denied
#0 0x7f883de2daee <unknown>
#1 0x7f883de400e2 <unknown>
#2 0x7f883de4145c <unknown>
#3 0x7f883e9b5b21 <unknown>
#4 0x7f883e9b62dd <unknown>
#5 0x7f883da4a527 <unknown>
#6 0x7f883d6f5d48 <unknown>
#7 0x7f883d6f9262 <unknown>
#8 0x7f883d4e7a9b <unknown>
#9 0x7f883d4e8bd5 <unknown>
#10 0x7f883d4d7bdd <unknown>
#11 0x7f883d4d7f0e QtWebEngineCore::WebContentsAdapter::WebContentsAdapter()
#12 0x7f8845342091 <unknown>
#13 0x7f8845342c04 QWebEnginePage::QWebEnginePage()
#14 0x7f8845351cfb QWebEngineView::page()
#15 0x7f8845352751 QWebEngineView::showEvent()
#16 0x7f8844c6f038 QWidget::event()
#17 0x7f8845352609 QWebEngineView::event()
#18 0x7f8844c3082c QApplicationPrivate::notify_helper()
#19 0x7f8844c380f4 QApplication::notify()
#20 0x7f8843eb29a8 QCoreApplication::notifyInternal2()
#21 0x7f8844c6bf08 QWidgetPrivate::show_helper()
#22 0x7f8844c6ebdb QWidget::setVisible()
#23 0x7f8844c6be30 QWidgetPrivate::showChildren()
#24 0x7f8844c6bedf QWidgetPrivate::show_helper()
#25 0x7f8844c6ebdb QWidget::setVisible()
#26 0x7f8844c6be30 QWidgetPrivate::showChildren()
#27 0x7f8844c6bedf QWidgetPrivate::show_helper()
#28 0x7f8844c6ebdb QWidget::setVisible()
#29 0x55ee0519d12d <unknown>
#30 0x7f88432b7b97 __libc_start_main
#31 0x55ee0519d1ea <unknown>

Installed Qt WebEngine locales directory not found at location /usr/share/qt5/translations/qtwebengine_locales. Trying application directory...
Qt WebEngine locales directory not found at location /snap/qtwebengine-snap/x1/usr/lib/x86_64-linux-gnu/qt5/libexec/qtwebengine_locales. Trying fallback directory... Translations MAY NOT not be correct.
Path override failed for key ui::DIR_LOCALES and path '/home/mazur/snap/qtwebengine-snap/x1/.QtWebEngineProcess'
Qt WebEngine resources not found at /usr/share/qt5/resources. Trying parent directory...
Qt WebEngine resources not found at /usr/share/qt5. Trying application directory...
Qt WebEngine resources not found at /snap/qtwebengine-snap/x1/usr/lib/x86_64-linux-gnu/qt5/libexec. Trying fallback directory... The application MAY NOT work.
[0711/152354.976594:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.QtWebEngineProcess/qtwebengine_resources.pak
Some features may not be available.
[0711/152354.979154:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.QtWebEngineProcess/qtwebengine_resources_100p.pak
Some features may not be available.
[0711/152354.979172:ERROR:resource_bundle.cc(759)] Failed to load /home/mazur/snap/qtwebengine-snap/x1/.QtWebEngineProcess/qtwebengine_resources_200p.pak
Some features may not be available.
[0711/152354.980096:WARNING:resource_bundle_qt.cpp(115)] locale_file_path.empty() for locale
[23190:23190:0711/152355.520588:FATAL:service_manager_context.cc(230)] Check failed: !contents.empty().
#0 0x7f883de2daee <unknown>
#1 0x7f883de400e2 <unknown>
#2 0x7f883d97d5bb <unknown>
#3 0x7f883d6f69cb <unknown>
#4 0x7f883d6f7e83 <unknown>
#5 0x7f883da0a9e9 <unknown>
#6 0x7f883d6f401b <unknown>
#7 0x7f883d6f92dc <unknown>
#8 0x7f883d4e7a9b <unknown>
#9 0x7f883d4e8bd5 <unknown>
#10 0x7f883d4d7bdd <unknown>
#11 0x7f883d4d7f0e QtWebEngineCore::WebContentsAdapter::WebContentsAdapter()
#12 0x7f8845342091 <unknown>
#13 0x7f8845342c04 QWebEnginePage::QWebEnginePage()
#14 0x7f8845351cfb QWebEngineView::page()
#15 0x7f8845352751 QWebEngineView::showEvent()
#16 0x7f8844c6f038 QWidget::event()
#17 0x7f8845352609 QWebEngineView::event()
#18 0x7f8844c3082c QApplicationPrivate::notify_helper()
#19 0x7f8844c380f4 QApplication::notify()
#20 0x7f8843eb29a8 QCoreApplication::notifyInternal2()
#21 0x7f8844c6bf08 QWidgetPrivate::show_helper()
#22 0x7f8844c6ebdb QWidget::setVisible()
#23 0x7f8844c6be30 QWidgetPrivate::showChildren()
#24 0x7f8844c6bedf QWidgetPrivate::show_helper()
#25 0x7f8844c6ebdb QWidget::setVisible()
#26 0x7f8844c6be30 QWidgetPrivate::showChildren()
#27 0x7f8844c6bedf QWidgetPrivate::show_helper()
#28 0x7f8844c6ebdb QWidget::setVisible()
#29 0x55ee0519d12d <unknown>
#30 0x7f88432b7b97 __libc_start_main
#31 0x55ee0519d1ea <unknown>

Aborted (core dumped)

All in all, there seems to be no (documented?) way of snapping an application using QtWebEngine.

[Marc Peña (pachulo)]

I'm having the same problem trying to snap the new version of nextcloud-client.

I've tried to solve it with a modification of snapcraft-desktop-helpers:
https://github.com/pachulo/snapcraft-desktop-helpers/commit/356dc11c0f374b3e30647d36554d4c4089670db5

But the result is the same.

[Marc Peña (pachulo)]

OK, I think I found a workaround: my snap started working after using this layout (more info here https://forum.snapcraft.io/t/layouts-re-mapping-snap-directories/1471):

layout:
    /usr/share/qt5:
        bind: $SNAP/usr/share/qt5

Let me know if it works for you too @teoretyk!

[Grzegorz Mazur (teoretyk)]

Marc, this is absolutely brilliant :) The layout specification apparently solves the Qt WebEngine resources issue. Unfortunately, the application still fails. After applying your fixes I get:

Qt: Session management error: None of the authentication protocols specified are supported
libpng warning: iCCP: known incorrect sRGB profile
[19042:19042:0724/145919.738713:FATAL:credentials.cc(155)] Check failed: NamespaceUtils::DenySetgroups(). : Permission denied
#0 0x7f514362caee <unknown>
#1 0x7f514363f0e2 <unknown>
#2 0x7f514364045c <unknown>
#3 0x7f51441b4b21 <unknown>
#4 0x7f51441b52dd <unknown>
#5 0x7f5143249527 <unknown>
#6 0x7f5142ef4d48 <unknown>
#7 0x7f5142ef8262 <unknown>
#8 0x7f5142ce6a9b <unknown>
#9 0x7f5142ce7bd5 <unknown>
#10 0x7f5142cd6bdd <unknown>
#11 0x7f5142cd6f0e QtWebEngineCore::WebContentsAdapter::WebContentsAdapter()
#12 0x7f514ab41091 <unknown>
#13 0x7f514ab41c04 QWebEnginePage::QWebEnginePage()
#14 0x7f514ab50cfb QWebEngineView::page()
#15 0x7f514ab51751 QWebEngineView::showEvent()
#16 0x7f514a46e038 QWidget::event()
#17 0x7f514ab51609 QWebEngineView::event()
#18 0x7f514a42f82c QApplicationPrivate::notify_helper()
#19 0x7f514a4370f4 QApplication::notify()
#20 0x7f51496b19a8 QCoreApplication::notifyInternal2()
#21 0x7f514a46af08 QWidgetPrivate::show_helper()
#22 0x7f514a46dbdb QWidget::setVisible()
#23 0x7f514a46ae30 QWidgetPrivate::showChildren()
#24 0x7f514a46aedf QWidgetPrivate::show_helper()
#25 0x7f514a46dbdb QWidget::setVisible()
#26 0x7f514a46ae30 QWidgetPrivate::showChildren()
#27 0x7f514a46aedf QWidgetPrivate::show_helper()
#28 0x7f514a46dbdb QWidget::setVisible()
#29 0x55efada7f12d <unknown>
#30 0x7f5148ab6b97 __libc_start_main
#31 0x55efada7f1ea <unknown>

[18779:18779:0724/145920.599254:ERROR:shared_memory_posix.cc(283)] Creating shared memory in /dev/shm/.org.chromium.Chromium.o4usDA failed: Permission denied
[18779:19052:0724/145920.680498:ERROR:zygote_host_impl_linux.cc(277)] Failed to adjust OOM score of renderer with pid 19062: Permission denied
[18779:19054:0724/145922.070590:ERROR:shared_memory_posix.cc(283)] Creating shared memory in /dev/shm/.org.chromium.Chromium.aPAPus failed: Permission denied
[19062:19062:0724/145922.070667:ERROR:broker_posix.cc(44)] Received unexpected number of handles
[18779:19054:0724/145922.071202:ERROR:shared_memory_posix.cc(283)] Creating shared memory in /dev/shm/.org.chromium.Chromium.epIjmk failed: Permission denied
[19062:19062:0724/145922.071266:ERROR:broker_posix.cc(44)] Received unexpected number of handles
[18779:19054:0724/145922.071501:ERROR:shared_memory_posix.cc(283)] Creating shared memory in /dev/shm/.org.chromium.Chromium.kn2Qdc failed: Permission denied
[19062:19062:0724/145922.071552:ERROR:broker_posix.cc(44)] Received unexpected number of handles
[18779:19054:0724/145922.071743:ERROR:shared_memory_posix.cc(283)] Creating shared memory in /dev/shm/.org.chromium.Chromium.Z64q53 failed: Permission denied
[19062:19062:0724/145922.071783:ERROR:broker_posix.cc(44)] Received unexpected number of handles

All these issues disappear (except for the first two quite harmless ones) when I install the snap in devmode, which IMHO means that this is the restriction put on ...