I noticed this today, but it may have been going since the release of kdeframeworks 5.33.

On my system, pretty much every KDE 5 binary segfaults on exit, *unless* it has opened its main window. For instance, if I run systemsettings once and then close the window, it exits cleanly. If I run it a second time while the first one is still open, this second instance crashes in QDBusConnectionPrivate::closeConnection().

KDE command line binaries crash just after printing their help text. Tested with kdesu, kde-open5 and kcmshell5. The latter crashes on exit only if it exits without opening the kcm window. Also noteworthy is that kcmshell4 never crashes.


Here's a gdb session from kcmshell5:

$ gdb kcmshell5  
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set scheduler-locking on
Reading symbols from kcmshell5...Reading symbols from /home/bernie/src/bernie/mandelwow/kcmshell5...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Missing separate debuginfos, use: dnf debuginfo-install kde-cli-tools-5.9.5-1.fc25.x86_64
(gdb) c
The program is not being run.
(gdb) r
Starting program: /usr/bin/kcmshell5 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7fffe40cc700 (LWP 30617)]
[New Thread 0x7fffdbd56700 (LWP 30618)]
Usage: /usr/bin/kcmshell5 [options] module
A tool to start single system settings modules

Options:
  -v, --version              Displays version information.
  -h, --help                 Displays this help.
  --author                   Show author information.
  --license                  Show license information.
  --desktopfile <file name>  The base file name of the desktop entry for this
                             application.
  --list                     List all possible modules
  --lang <language>          Specify a particular language
  --silent                   Do not display main window
  --args <arguments>         Arguments for the module
  --icon <icon>              Use a specific icon for the window
  --caption <caption>        Use a specific caption for the window

Arguments:
  module                     Configuration module to open

Thread 3 "QDBusConnection" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffdbd56700 (LWP 30618)]
0x00007ffff5404f8d in QObject::disconnect(QObject const*, char const*, QObject const*, char const*) () from /lib64/libQt5Core.so.5
(gdb) bt
#0  0x00007ffff5404f8d in QObject::disconnect(QObject const*, char const*, QObject const*, char const*) () at /lib64/libQt5Core.so.5
#1  0x00007ffff7f22fb0 in QDBusConnectionPrivate::closeConnection() () at /lib64/libQt5DBus.so.5
#2  0x00007ffff7f0f852 in QDBusConnectionManager::run() () at /lib64/libQt5DBus.so.5
#3  0x00007ffff523a9ca in QThreadPrivate::start(void*) () at /lib64/libQt5Core.so.5
#4  0x00007ffff29cd6ca in start_thread () at /lib64/libpthread.so.0
#5  0x00007ffff462df7f in clone () at /lib64/libc.so.6