Looks like somehow your list of projects got screwed. Please try deleting $HOME/.kde/share/apps/kdevelop/sessions/ and then start the IDE again.

(In reply to comment #1)
> Looks like somehow your list of projects got screwed. Please try deleting
> $HOME/.kde/share/apps/kdevelop/sessions/ and then start the IDE again.

Okay, that did it. I'm using KDev 3 too, that might have caused the havoc.
But still when opening a kdev4 project file, or trying to create one, I got crashes... Here is the crash report on that one:


Application: KDevelop (kdevelop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f9819a84820 (LWP 24451))]

Thread 2 (Thread 0x7f980f657910 (LWP 24452)):
#0  0x00000039ac60b57d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x0000003bcc45ad12 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib64/libQtCore.so.4
#2  0x00007f981a403bae in KDevelop::DUChainPrivate::CleanupThread::run (this=0x2632800) at /home/patrick/tmp/KDevelop/kdevplatform/language/duchain/duchain.cpp:280
#3  0x0000003bcc459cf5 in ?? () from /usr/lib64/libQtCore.so.4
#4  0x00000039ac60686a in start_thread () from /lib64/libpthread.so.0
#5  0x00000039abade3bd in clone () from /lib64/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f9819a84820 (LWP 24451)):
[KCrash Handler]
#5  0x0000000000607d20 in QListData::shared_null ()
#6  0x00007f981ac7b25e in KDevelop::ProjectController::isProjectNameUsed (this=<value optimized out>, name=@0x231f600) at /home/patrick/tmp/KDevelop/kdevplatform/shell/projectcontroller.cpp:806
#7  0x00007f980d736c11 in ?? () from /usr/lib64/kde4/kdevappwizard.so
#8  0x00007f980d735d16 in ?? () from /usr/lib64/kde4/kdevappwizard.so
#9  0x00007f980d7343d4 in ?? () from /usr/lib64/kde4/kdevappwizard.so
#10 0x00007f980d734640 in ?? () from /usr/lib64/kde4/kdevappwizard.so
#11 0x0000003bcc553dcc in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib64/libQtCore.so.4
#12 0x0000003bcd7897f7 in QAction::triggered(bool) () from /usr/lib64/libQtGui.so.4
#13 0x0000003bcd78ac5f in QAction::activate(QAction::ActionEvent) () from /usr/lib64/libQtGui.so.4
#14 0x0000003bcdb73175 in ?? () from /usr/lib64/libQtGui.so.4
#15 0x0000003bcdb7905a in ?? () from /usr/lib64/libQtGui.so.4
#16 0x0000003bceae325e in KMenu::mouseReleaseEvent(QMouseEvent*) () from /usr/lib64/libkdeui.so.5
#17 0x0000003bcd7ddda8 in QWidget::event(QEvent*) () from /usr/lib64/libQtGui.so.4
#18 0x0000003bcdb7b7c3 in QMenu::event(QEvent*) () from /usr/lib64/libQtGui.so.4
#19 0x0000003bcd78f63c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#20 0x0000003bcd7966e1 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#21 0x0000003bcea117f6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#22 0x0000003bcc53ebac in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQtCore.so.4
#23 0x0000003bcd795fd0 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&) () from /usr/lib64/libQtGui.so.4
#24 0x0000003bcd7fbe9e in ?? () from /usr/lib64/libQtGui.so.4
#25 0x0000003bcd7fab38 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib64/libQtGui.so.4
#26 0x0000003bcd82287c in ?? () from /usr/lib64/libQtGui.so.4
#27 0x00000039aee3790e in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#28 0x00000039aee3b0e8 in ?? () from /lib64/libglib-2.0.so.0
#29 0x00000039aee3b20a in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#30 0x0000003bcc566f36 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#31 0x0000003bcd82202e in ?? () from /usr/lib64/libQtGui.so.4
#32 0x0000003bcc53d4b2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#33 0x0000003bcc53d884 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#34 0x0000003bcc53fa19 in QCoreApplication::exec() () from /usr/lib64/libQtCore.so.4
#35 0x0000000000405b37 in main (argc=<value optimized out>, argv=<value optimized out>) at /home/patrick/tmp/KDevelop/kdevelop/app/main.cpp:193

You should remove kdevelop3 and any other kdevelop or kdevplatform packages you have on your system before starting to use kdevelop4.

If you still get crashes after doing that: Which version of libc 2.10 is installed on your system?

(In reply to comment #3)
> You should remove kdevelop3 and any other kdevelop or kdevplatform packages you
> have on your system before starting to use kdevelop4.
> If you still get crashes after doing that: Which version of libc 2.10 is
> installed on your system?

I remove kdevelop, kdevelop-libs, kdevplatform, kdevplatform-libs. But then I can even not create a new project ("New from template). That option is then missing...

I got glibc-2.10.1-5.x86_64 .... (yes, it's all 64 bot of course)
So, installed kdevelop 3 back, to be able to continue my work ...
And then, just trying again v4, the new from template option is back there, so it seems, I'm missing something ....

This is my update/compile script (yes, I installed anything locally to avoid problems with the main distro/applications):

cd /home/patrick/tmp/KDevelop
cd kdevelop/build
make uninstall
cd ../../kdevplatform/build
make uninstall
svn up ..
make
make install
cd -
svn up ..
make
make install

Ok, so you probably have both problems at the same time. Having packages installed from possibly older versions of kdevelop4 or kdevelop3 will cause crashes in random places. To get the "New Project" and other entries back you need to make sure that KDevelop finds its plugins. For that see the compilation instructions on our wiki, specifically look for KDEDIRS (http://www.kdevelop.org/mediawiki/index.php/KDevelop_4/compiling)

Additionally look into the original bugreport regarding malloc_check_ how to avoid the known crashes with libc2.10. A link will be appended to this message.

*** This bug has been marked as a duplicate of bug 206775 ***