Qt Designer fails to launch

Asked by Matheus on 2019-11-02

Qt Designer used to work fine until the most recent updates. I am on Kubuntu 18.04.3 LTS:

```
$ designer
QMetaProperty::read: Unable to handle unregistered datatype 'SelectionBehavior' for property 'QTabBar::selectionBehaviorOnRemove'
Error while reparenting!
Designer: A class name mismatch occurred when creating a widget using the custom widget factory registered for widgets of class KDialog. It returned a
widget of class QDialog.
KCrash: crashing... crashRecursionCounter = 2
KCrash: Application Name = designer path = /usr/lib/qt5/bin pid = 30169
KCrash: Arguments: /usr/lib/qt5/bin/designer
KCrash: Attempting to start /usr/lib/x86_64-linux-gnu/libexec/drkonqi from kdeinit
sock_file=/run/user/1000/kdeinit5__0

[1]+ Stopped designer

-------------------------------------------------------------------------------------------------------------------------------------------------------------
Application: designer (designer), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff246f48780 (LWP 26959))]

Thread 5 (Thread 0x7ff1ea7d6700 (LWP 26964)):
#0 0x00007ff243c48bf9 in __GI___poll (fds=0x7ff1dc004a10, nfds=1, timeout=334) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007ff241aae5c9 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ff241aae6dc in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ff24459199b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4 0x00007ff2445369fa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5 0x00007ff24435523a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6 0x00007ff24435a17d in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7 0x00007ff24357e6db in start_thread (arg=0x7ff1ea7d6700) at pthread_create.c:463
#8 0x00007ff243c5588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7ff1eb27d700 (LWP 26963)):
#0 0x00007ff243c48bf9 in __GI___poll (fds=0x7ff1e4019ed0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007ff241aae5c9 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ff241aae6dc in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ff24459199b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4 0x00007ff2445369fa in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5 0x00007ff24435523a in QThread::exec() () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6 0x00007ff23d856d45 in () at /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7 0x00007ff24435a17d in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8 0x00007ff24357e6db in start_thread (arg=0x7ff1eb27d700) at pthread_create.c:463
#9 0x00007ff243c5588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7ff205aca700 (LWP 26962)):
#0 0x00007ff2435849f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7ff21939e110) at ../sysdeps/unix/sysv/linux/futex-internal.h:88
#1 0x00007ff2435849f3 in __pthread_cond_wait_common (abstime=0x0, mutex=0x5623c7560f50, cond=0x7ff21939e0e8) at pthread_cond_wait.c:502
#2 0x00007ff2435849f3 in __pthread_cond_wait (cond=0x7ff21939e0e8, mutex=0x5623c7560f50) at pthread_cond_wait.c:655
#3 0x00007ff243fdc86c in std::condition_variable::wait(std::unique_lock<std::mutex>&) () at /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4 0x00007ff2186df0a7 in () at /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#5 0x00007ff2186df1e9 in () at /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#6 0x00007ff243fe266f in () at /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7 0x00007ff24357e6db in start_thread (arg=0x7ff205aca700) at pthread_create.c:463
#8 0x00007ff243c5588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7ff239ccd700 (LWP 26960)):
#0 0x00007ff243c48bf9 in __GI___poll (fds=0x7ff239cccd28, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007ff23ed2a747 in () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2 0x00007ff23ed2c36a in xcb_wait_for_event () at /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3 0x00007ff23dd4a5e9 in () at /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#4 0x00007ff24435a17d in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5 0x00007ff24357e6db in start_thread (arg=0x7ff239ccd700) at pthread_create.c:463
#6 0x00007ff243c5588f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ff246f48780 (LWP 26959)):
[KCrash Handler]
#6 0x00007ff244564ee0 in QObject::thread() const () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7 0x00007ff21a614c7e in QgsAuthManager::authDatabaseConnection() const () at /usr/lib/libqgis_core.so.3.10.0
#8 0x00007ff21a61580b in QgsAuthManager::availableAuthMethodConfigs(QString const&) () at /usr/lib/libqgis_core.so.3.10.0
#9 0x00007ff21b87bf4e in QgsAuthConfigSelect::loadAvailableConfigs() () at /usr/lib/libqgis_gui.so.3.10.0
#10 0x00007ff21b87c87c in QgsAuthConfigSelect::populateConfigSelector() () at /usr/lib/libqgis_gui.so.3.10.0
#11 0x00007ff21b87dfc3 in QgsAuthConfigSelect::QgsAuthConfigSelect(QWidget*, QString const&) () at /usr/lib/libqgis_gui.so.3.10.0
#12 0x00007ff21c207cc4 in QgsAuthConfigSelectPlugin::createWidget(QWidget*) () at /usr/lib/x86_64-linux-gnu/qt5/plugins/designer/libqgis_customwidgets.so.3.10.0
#13 0x00007ff246383c18 in qdesigner_internal::WidgetFactory::createCustomWidget(QString const&, QWidget*, bool*) const () at /usr/lib/x86_64-linux-gnu/libQt5Designer.so.5
#14 0x00007ff24638446d in qdesigner_internal::WidgetFactory::createWidget(QString const&, QWidget*) const () at /usr/lib/x86_64-linux-gnu/libQt5Designer.so.5
#15 0x00007ff24638dc0f in qdesigner_internal::WidgetDataBase::defaultPropertyValues(QString const&) () at /usr/lib/x86_64-linux-gnu/libQt5Designer.so.5
#16 0x00007ff24638ddc6 in qdesigner_internal::WidgetDataBase::grabDefaultPropertyValues() () at /usr/lib/x86_64-linux-gnu/libQt5Designer.so.5
#17 0x00005623c5f2f5d6 in ()
#18 0x00005623c5f285a7 in ()
#19 0x00005623c5f16d16 in ()
#20 0x00007ff243b55b97 in __libc_start_main (main=0x5623c5f16cc0, argc=1, argv=0x7ffcfd751c38, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffcfd751c28) at ../csu/libc-start.c:310
#21 0x00005623c5f16dea in ()
```

Could that be a bug? I found that it could be caused due to a KDE plugin bug. I don't really use those so is there a way to launch it without those plugins or uninstall them? I would be happy with just the default thing working. I tried adding to .config/QtProject/Designer.conf:

```
[PluginManager]
DisabledPlugins=/usr/lib/qt/plugins/designer/kdewebkit5widgets.so, /usr/lib/qt/plugins/designer/kf5deprecatedwidgets.so, /usr/lib/qt/plugins/designer/kf5widgets.so
```
But didn't help. I have An alternative Qt installation with version 5.12.3 and it's Designer works fine, but I am still interested on having the default one too working.

Question information

Language:
English Edit question
Status:
Needs information
For:
Ubuntu Edit question
Assignee:
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Last query:
2019-11-02
Last reply:
2019-11-02

What is the output of:

apt-cache policy qt 4-designer

Thanks

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