Arch Linux

Run digikam from a command line and paste output

$ export LC_ALL=C
$ digikam
Bus error

$gdb digikam
GNU gdb (GDB) 7.3.1
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/digikam...(no debugging symbols found)...done.
(gdb) r
Starting program: /usr/bin/digikam
[Thread debugging using libthread_db enabled]

Program received signal SIGBUS, Bus error.
0x00007ffff2a96ad7 in ?? () from /usr/lib/libkdecore.so.5

(gdb) bt
#0 0x00007ffff2a96ad7 in ?? () from /usr/lib/libkdecore.so.5
#1 0x00007ffff2a926a7 in ?? () from /usr/lib/libkdecore.so.5
#2 0x00007ffff2a92d47 in KSharedDataCache::find(QString const&, QByteArray*) const () from /usr/lib/libkdecore.so.5
#3 0x00007ffff3bb9869 in ?? () from /usr/lib/libkdeui.so.5
#4 0x00007ffff3bb9b81 in KIconLoader::loadIcon(QString const&, KIconLoader::Group, int, int, QStringList const&, QString*, bool) const ()
from /usr/lib/libkdeui.so.5
#5 0x00007ffff3bb142f in ?? () from /usr/lib/libkdeui.so.5
#6 0x00007ffff2f93f15 in QIcon::pixmap(QSize const&, QIcon::Mode, QIcon::State) const () from /usr/lib/libQtGui.so.4
#7 0x00007ffff2f888bb in QWidgetPrivate::setWindowIcon_sys(bool) ()
from /usr/lib/libQtGui.so.4
#8 0x00007ffff2f3f382 in QWidget::event(QEvent*) ()
from /usr/lib/libQtGui.so.4
#9 0x00007ffff2eeeae4 in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() from /usr/lib/libQtGui.so.4
#10 0x00007ffff2ef3951 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/libQtGui.so.4
#11 0x00007ffff3c0abb6 in KApplication::notify(QObject*, QEvent*) ()
from /usr/lib/libkdeui.so.5
#12 0x00007ffff252089c in QCoreApplication::notifyInternal(QObject*, QEvent*)
() from /usr/lib/libQtCore.so.4
---Type <return> to continue, or q <return> to quit---
#13 0x00007ffff2ef0b63 in QApplication::setWindowIcon(QIcon const&) ()
from /usr/lib/libQtGui.so.4
#14 0x00007ffff3c09212 in ?? () from /usr/lib/libkdeui.so.5
#15 0x00007ffff3c0c05c in ?? () from /usr/lib/libkdeui.so.5
#16 0x00007ffff3c0d0b8 in KApplication::KApplication(bool) ()
from /usr/lib/libkdeui.so.5
#17 0x000000000048a5a3 in ?? ()
#18 0x00007ffff166c13d in __libc_start_main () from /lib/libc.so.6
#19 0x000000000048c875 in _start ()

Also submitted to http://bugs.kde.org/show_bug.cgi?id=286341

Solved by doing "rm /var/tmp/kdecache-* -rf" does the trick.
Cf : https://bugs.kde.org/show_bug.cgi?id=284770 and https://bugs.kde.org/show_bug.cgi?id=286341