Still happening with 4.7.80. But backtrace seems to have slightly more information.

Application: Blogilo (blogilo), signal: Illegal instruction
[Current thread is 1 (Thread 0x7f815d3b3760 (LWP 9816))]

Thread 3 (Thread 0x7f8147bbf700 (LWP 9817)):
#0  pthread_cond_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f815bf044fd in WTF::TCMalloc_PageHeap::scavengerThread (this=<value optimized out>) at wtf/FastMalloc.cpp:2378
#2  0x00007f815bf04609 in WTF::TCMalloc_PageHeap::runScavengerThread (context=0x7f815c6b7f34) at wtf/FastMalloc.cpp:1497
#3  0x00007f8155dcedba in start_thread (arg=<value optimized out>) at pthread_create.c:301
#4  0x00007f8157f5002d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 2 (Thread 0x7f81472be700 (LWP 9818)):
#0  0x00007f8157f47293 in __poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f81531c7ee1 in g_main_context_poll (context=0x1a95280, block=<value optimized out>, dispatch=<value optimized out>, self=<value optimized out>) at gmain.c:3405
#2  g_main_context_iterate (context=0x1a95280, block=<value optimized out>, dispatch=<value optimized out>, self=<value optimized out>) at gmain.c:3087
#3  0x00007f81531c831e in g_main_context_iteration (context=0x1a95280, may_block=1) at gmain.c:3155
#4  0x00007f8158904c56 in QEventDispatcherGlib::processEvents (this=0x1a70380, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#5  0x00007f81588d8e12 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007f81588d9094 in QEventLoop::exec (this=0x7f81472bde20, flags=...) at kernel/qeventloop.cpp:201
#7  0x00007f81587eeee4 in QThread::exec (this=<value optimized out>) at thread/qthread.cpp:498
#8  0x00007f81587f1765 in QThreadPrivate::start (arg=0x195a980) at thread/qthread_unix.cpp:331
#9  0x00007f8155dcedba in start_thread (arg=<value optimized out>) at pthread_create.c:301
#10 0x00007f8157f5002d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 1 (Thread 0x7f815d3b3760 (LWP 9816)):
[KCrash Handler]
#6  0x00007f815be8d188 in writeTo (string1=0x7f815c11eac0 "Result of expression '", string2=<value optimized out>, string3=<value optimized out>, string4=<value optimized out>, string6=<value optimized out>, string7=<value optimized out>, string5=<value optimized out>) at runtime/UString.h:298
#7  tryMakeString<char const*, JSC::UString, char const*, JSC::UString, char const*, JSC::UString, char const*> (string1=0x7f815c11eac0 "Result of expression '", string2=<value optimized out>, string3=<value optimized out>, string4=<value optimized out>, string6=<value optimized out>, string7=<value optimized out>, string5=<value optimized out>) at runtime/UString.h:523
#8  JSC::makeString<char const*, JSC::UString, char const*, JSC::UString, char const*, JSC::UString, char const*> (string1=0x7f815c11eac0 "Result of expression '", string2=<value optimized out>, string3=<value optimized out>, string4=<value optimized out>, string6=<value optimized out>, string7=<value optimized out>, string5=<value optimized out>) at runtime/UString.h:636
#9  0x00007f815be8da4c in JSC::createErrorMessage (exec=0x7f8145e2d098, codeBlock=<value optimized out>, expressionStart=666, expressionStop=695, value=..., error=) at runtime/ExceptionHelpers.cpp:92
#10 0x00007f815be8ecc5 in JSC::createNotAnObjectError (exec=0x7f8145e2d098, error=0x7f8145dc3340, bytecodeOffset=<value optimized out>, codeBlock=0x7f8147329d80) at runtime/ExceptionHelpers.cpp:183
#11 0x00007f815be59cea in JSC::Interpreter::throwException (this=0x7f81472d1f20, callFrame=@0x7fff429c2308, exceptionValue=..., bytecodeOffset=21, explicitThrow=false) at interpreter/Interpreter.cpp:500
#12 0x00007f815be6f1bf in JSC::cti_vm_throw (args=<value optimized out>) at jit/JITStubs.cpp:3128
#13 0x00007f815be6c120 in ctiVMThrowTrampoline () from /usr/lib64/qt4/libQtWebKit.so.4
#14 0x0000000000000000 in ?? ()

The backtrace seems to indicate that you are using QtWebKit from Qt 4.7.3. If this is reproducible, could you try Qt 4.8.0, which comes with a much improved QtWebKit?

There are some problems with qt 4.8 on gentoo apparently: https://bugs.gentoo.org/show_bug.cgi?id=394903 I'll have to wait until it's sorted out.

Yes, qt-4.8 and blogilo starts ok for me. As I am the only one affected, I mark this as fixed.

Oh strange thing happened. When I started my computer today, it had no network connection due to malfunctioning switch. Because of that I didn't enter kwallet password, becasue that dialog poped-up somewhere in background. Without it, blogilo started although I was missing configuration options and any accounts. Becasue other PIM apps were crashing for me I logged out and in again. Now blogilo doesn't start again.

Terminal output:

ctibor@thuban ~ $ blogilo 
Blogilo   1.1 
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
QDBusConnection: session D-Bus connection created before QCoreApplication. Application may misbehave.
ctibor@thuban ~ $ KCrash: Application 'blogilo' crashing...
KCrash: Attempting to start /usr/lib64/kde4/libexec/drkonqi from kdeinit
sock_file=/home/ctibor/.kde4/socket-thuban/kdeinit4__0

Backtrace from drkonqui:

Thread 1 (Thread 0x7f5d3206a760 (LWP 303)):
[KCrash Handler]
#6  0x00007f5d3096ed2f in ARC4Stream (this=0x284f980) at wtf/CryptographicallyRandomNumber.cpp:175
#7  ARC4RandomNumberGenerator (this=0x284f980) at wtf/CryptographicallyRandomNumber.cpp:83
#8  sharedRandomNumberGenerator () at wtf/CryptographicallyRandomNumber.cpp:169
#9  WTF::cryptographicallyRandomNumber () at wtf/CryptographicallyRandomNumber.cpp:177
#10 0x00007f5d3098c0b9 in WTF::randomNumber () at wtf/RandomNumber.cpp:57
#11 0x00007f5d30836b39 in JSGlobalObject (thisValue=0x7f5cd92c4150, structure=<optimized out>, globalData=<optimized out>, this=0x7f5cd92b8150) at ../JavaScriptCore/runtime/JSGlobalObject.h:137
#12 WebCore::JSDOMGlobalObject::JSDOMGlobalObject (this=<optimized out>, globalData=<optimized out>, structure=<optimized out>, world=..., thisValue=<optimized out>) at bindings/js/JSDOMGlobalObject.cpp:48
#13 0x00007f5d30107b50 in WebCore::JSDOMWindowBase::JSDOMWindowBase (this=0x7f5cd92b8150, globalData=<optimized out>, structure=<optimized out>, window=..., shell=0x7f5cd92c4150) at bindings/js/JSDOMWindowBase.cpp:50
#14 0x00007f5d2fe82d8e in WebCore::JSDOMWindow::JSDOMWindow (this=0x7f5cd92b8150, globalData=<optimized out>, structure=<optimized out>, impl=<optimized out>, shell=<optimized out>) at ../../WebCore/generated/JSDOMWindow.cpp:1058
#15 0x00007f5d30112737 in WebCore::JSDOMWindowShell::setWindow (this=0x7f5cd92c4150, domWindow=...) at bindings/js/JSDOMWindowShell.cpp:67
#16 0x00007f5d30112972 in WebCore::JSDOMWindowShell::JSDOMWindowShell (this=0x7f5cd92c4150, window=..., world=0x7f5d1a170e60) at bindings/js/JSDOMWindowShell.cpp:51
#17 0x00007f5d30158bf0 in WebCore::ScriptController::createWindowShell (this=0x7f5d1a17e818, world=0x7f5d1a170e60) at bindings/js/ScriptController.cpp:112
#18 0x00007f5d3015946a in WebCore::ScriptController::initScript (this=0x7f5d1a17e818, world=0x7f5d1a170e60) at bindings/js/ScriptController.cpp:218
#19 0x00007f5d30159c73 in windowShell (world=0x7f5d1a170e60, this=0x7f5d1a17e818) at bindings/js/ScriptController.h:79
#20 WebCore::ScriptController::evaluateInWorld (this=0x7f5d1a17e818, sourceCode=..., world=0x7f5d1a170e60) at bindings/js/ScriptController.cpp:131
#21 0x00007f5d3015a362 in WebCore::ScriptController::evaluate (this=0x7f5d1a17e818, sourceCode=...) at bindings/js/ScriptController.cpp:166
#22 0x00007f5d30265dce in WebCore::ScriptElement::executeScript (this=0x7f5d1a1b9e38, sourceCode=...) at dom/ScriptElement.cpp:283
#23 0x00007f5d3026995d in WebCore::ScriptElement::prepareScript (this=0x7f5d1a1b9e38, scriptStartPosition=..., supportLegacyTypes=WebCore::ScriptElement::DisallowLegacyTypeInTypeAttribute) at dom/ScriptElement.cpp:240
#24 0x00007f5d30392d69 in WebCore::HTMLScriptRunner::runScript (this=0x7f5d1a178420, script=0x7f5d1a1b9dc0, scriptStartPosition=...) at html/parser/HTMLScriptRunner.cpp:296
#25 0x00007f5d3039374d in WebCore::HTMLScriptRunner::execute (this=0x7f5d1a178420, scriptElement=..., scriptStartPosition=...) at html/parser/HTMLScriptRunner.cpp:170
#26 0x00007f5d3038723b in WebCore::HTMLDocumentParser::runScriptsForPausedTreeBuilder (this=0x7f5d1a1b3600) at html/parser/HTMLDocumentParser.cpp:205
#27 0x00007f5d3038733e in WebCore::HTMLDocumentParser::canTakeNextToken (this=0x7f5d1a1b3600, mode=WebCore::HTMLDocumentParser::AllowYield, session=<optimized out>) at html/parser/HTMLDocumentParser.cpp:223
#28 0x00007f5d30388a0e in WebCore::HTMLDocumentParser::pumpTokenizer (this=0x7f5d1a1b3600, mode=WebCore::HTMLDocumentParser::AllowYield) at html/parser/HTMLDocumentParser.cpp:261
#29 0x00007f5d3038941a in WebCore::HTMLDocumentParser::append (this=0x7f5d1a1b3600, source=...) at html/parser/HTMLDocumentParser.cpp:367
#30 0x00007f5d3086f001 in WebCore::DecodedDataDocumentParser::appendBytes (this=0x7f5d1a1b3600, writer=0x7f5d1a17b070, data=<optimized out>, length=<optimized out>, shouldFlush=<optimized out>) at dom/DecodedDataDocumentParser.cpp:54
#31 0x00007f5d3041f51d in WebCore::DocumentLoader::commitData (this=0x7f5d1a17b000, bytes=0x7f5d1a1c3400 "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"application/xhtml+xml; charset=UTF-8\" />\n<script type=\"text/javascript\">\n\nfunction mouseEventHandler(mEvent)\n{\n//    var node = mEvent.srcElement"..., length=2470) at loader/DocumentLoader.cpp:321
#32 0x00007f5d300c631d in WebCore::FrameLoaderClientQt::committedLoad (this=0x2818c50, loader=0x7f5d1a17b000, data=0x7f5d1a1c3400 "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"application/xhtml+xml; charset=UTF-8\" />\n<script type=\"text/javascript\">\n\nfunction mouseEventHandler(mEvent)\n{\n//    var node = mEvent.srcElement"..., length=2470) at WebCoreSupport/FrameLoaderClientQt.cpp:901
#33 0x00007f5d3041faca in WebCore::DocumentLoader::commitLoad (this=0x7f5d1a17b000, data=0x7f5d1a1c3400 "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"application/xhtml+xml; charset=UTF-8\" />\n<script type=\"text/javascript\">\n\nfunction mouseEventHandler(mEvent)\n{\n//    var node = mEvent.srcElement"..., length=2470) at loader/DocumentLoader.cpp:307
#34 0x00007f5d30459fb0 in WebCore::ResourceLoader::didReceiveData (this=0x7f5d1a1ae680, data=0x7f5d1a1c3400 "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"application/xhtml+xml; charset=UTF-8\" />\n<script type=\"text/javascript\">\n\nfunction mouseEventHandler(mEvent)\n{\n//    var node = mEvent.srcElement"..., length=2470, encodedDataLength=2470, allAtOnce=<optimized out>) at loader/ResourceLoader.cpp:279
#35 0x00007f5d30446ab4 in WebCore::MainResourceLoader::didReceiveData (this=0x7f5d1a1ae680, data=0x7f5d1a1c3400 "<html>\n<head>\n<meta http-equiv=\"Content-Type\" content=\"application/xhtml+xml; charset=UTF-8\" />\n<script type=\"text/javascript\">\n\nfunction mouseEventHandler(mEvent)\n{\n//    var node = mEvent.srcElement"..., length=2470, encodedDataLength=2470, allAtOnce=true) at loader/MainResourceLoader.cpp:463
#36 0x00007f5d30446f2d in WebCore::MainResourceLoader::continueAfterContentPolicy (this=0x7f5d1a1ae680, contentPolicy=<optimized out>, r=<optimized out>) at loader/MainResourceLoader.cpp:315
#37 0x00007f5d30447626 in WebCore::MainResourceLoader::continueAfterContentPolicy (this=0x7f5d1a1ae680, policy=WebCore::PolicyUse) at loader/MainResourceLoader.cpp:333
#38 0x00007f5d3044ac74 in callContinueAfterContentPolicy (policy=WebCore::PolicyUse, argument=0x7f5d1a1ae680) at loader/MainResourceLoader.cpp:325
#39 WebCore::MainResourceLoader::didReceiveResponse (this=0x7f5d1a1ae680, r=...) at loader/MainResourceLoader.cpp:423
#40 0x00007f5d3044885a in WebCore::MainResourceLoader::handleDataLoadNow (this=0x7f5d1a1ae680) at loader/MainResourceLoader.cpp:533
#41 0x00007f5d304492a2 in WebCore::MainResourceLoader::loadNow (this=0x7f5d1a1ae680, r=...) at loader/MainResourceLoader.cpp:581
#42 0x00007f5d3044b599 in WebCore::MainResourceLoader::load (this=0x7f5d1a1ae680, r=..., substituteData=<optimized out>) at loader/MainResourceLoader.cpp:612
#43 0x00007f5d3041fd64 in WebCore::DocumentLoader::startLoadingMainResource (this=0x7f5d1a17b000, identifier=<optimized out>) at loader/DocumentLoader.cpp:798
#44 0x00007f5d3042a8e9 in WebCore::FrameLoader::continueLoadAfterWillSubmitForm (this=0x7f5d1a17e478) at loader/FrameLoader.cpp:2572
#45 0x00007f5d30435df0 in WebCore::FrameLoader::continueLoadAfterNavigationPolicy (this=0x7f5d1a17e478, formState=..., shouldContinue=true) at loader/FrameLoader.cpp:3105
#46 0x00007f5d30435e40 in WebCore::FrameLoader::callContinueLoadAfterNavigationPolicy (argument=<optimized out>, request=<optimized out>, formState=<optimized out>, shouldContinue=<optimized out>) at loader/FrameLoader.cpp:2978
#47 0x00007f5d30451792 in WebCore::PolicyChecker::checkNavigationPolicy (this=0x7f5d1a17e488, request=..., loader=0x7f5d1a17b000, formState=..., function=0x7f5d30435e20 <WebCore::FrameLoader::callContinueLoadAfterNavigationPolicy(void*, WebCore::ResourceRequest const&, WTF::PassRefPtr<WebCore::FormState>, bool)>, argument=0x7f5d1a17e478) at loader/PolicyChecker.cpp:68
#48 0x00007f5d304363de in WebCore::FrameLoader::loadWithDocumentLoader (this=0x7f5d1a17e478, loader=0x7f5d1a17b000, type=<optimized out>, prpFormState=<optimized out>) at loader/FrameLoader.cpp:1586
#49 0x00007f5d3043660c in WebCore::FrameLoader::load (this=0x7f5d1a17e478, newDocumentLoader=0x7f5d1a17b000) at loader/FrameLoader.cpp:1527
#50 0x00007f5d3043675b in WebCore::FrameLoader::load (this=0x7f5d1a17e478, request=<optimized out>, substituteData=<optimized out>, lockHistory=<optimized out>) at loader/FrameLoader.cpp:1463
#51 0x00007f5d3008bce0 in QWebFrame::setContent (this=0x28a3170, data=<optimized out>, mimeType=<optimized out>, baseUrl=<optimized out>) at Api/qwebframe.cpp:1004
#52 0x000000000046b11b in TextEditor::TextEditor (this=0x279ae50, parent=<optimized out>) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/composer/texteditor.cpp:214
#53 0x00000000004344d7 in PostEntry::createUi (this=0x281cb20) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/postentry.cpp:136
#54 0x000000000043487d in PostEntry::PostEntry (this=0x281cb20, parent=<optimized out>) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/postentry.cpp:97
#55 0x000000000041e983 in MainWindow::createPostEntry (this=0x2726f10, blog_id=-1, post=...) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/mainwindow.cpp:618
#56 0x000000000041ee9f in MainWindow::slotCreateNewPost (this=0x2726f10) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/mainwindow.cpp:266
#57 0x000000000041f4f0 in MainWindow::loadTempPosts (this=0x2726f10) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/mainwindow.cpp:213
#58 0x00007f5d2cfd8abe in QObject::event (this=0x2726f10, e=<optimized out>) at kernel/qobject.cpp:1195
#59 0x00007f5d2da4455c in QWidget::event (this=0x2726f10, event=0x292f8d0) at kernel/qwidget.cpp:8820
#60 0x00007f5d2de0e653 in QMainWindow::event (this=0x2726f10, event=0x292f8d0) at widgets/qmainwindow.cpp:1478
#61 0x00007f5d31b64e59 in KXmlGuiWindow::event (this=0x2726f10, ev=0x292f8d0) at /var/tmp/portage/kde-base/kdelibs-4.7.95/work/kdelibs-4.7.95/kdeui/xmlgui/kxmlguiwindow.cpp:126
#62 0x00007f5d2d9f2d3c in QApplicationPrivate::notify_helper (this=0x24ddb40, receiver=0x2726f10, e=0x292f8d0) at kernel/qapplication.cpp:4550
#63 0x00007f5d2d9f792f in QApplication::notify (this=<optimized out>, receiver=0x2726f10, e=0x292f8d0) at kernel/qapplication.cpp:4411
#64 0x00007f5d31a65fe8 in KApplication::notify (this=0x7fffaf5556b0, receiver=0x2726f10, event=0x292f8d0) at /var/tmp/portage/kde-base/kdelibs-4.7.95/work/kdelibs-4.7.95/kdeui/kernel/kapplication.cpp:311
#65 0x00007f5d2cfc3d4b in QCoreApplication::notifyInternal (this=0x7fffaf5556b0, receiver=0x2726f10, event=0x292f8d0) at kernel/qcoreapplication.cpp:876
#66 0x00007f5d2cfc7347 in sendEvent (event=0x292f8d0, receiver=0x2726f10) at kernel/qcoreapplication.h:231
#67 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x2497920) at kernel/qcoreapplication.cpp:1500
#68 0x00007f5d2cff2df3 in sendPostedEvents () at kernel/qcoreapplication.h:236
#69 postEventSourceDispatch (s=<optimized out>) at kernel/qeventdispatcher_glib.cpp:279
#70 0x00007f5d28a8d01a in g_main_dispatch (context=0x24e00e0) at gmain.c:2441
#71 g_main_context_dispatch (context=0x24e00e0) at gmain.c:3011
#72 0x00007f5d28a8d828 in g_main_context_iterate (context=0x24e00e0, block=1, dispatch=1, self=<optimized out>) at gmain.c:3089
#73 0x00007f5d28a8d9bf in g_main_context_iteration (context=0x24e00e0, may_block=1) at gmain.c:3152
#74 0x00007f5d2cff2f5a in QEventDispatcherGlib::processEvents (this=0x2497180, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#75 0x00007f5d2da98fe6 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#76 0x00007f5d2cfc2cf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#77 0x00007f5d2cfc2fe5 in QEventLoop::exec (this=0x7fffaf555600, flags=...) at kernel/qeventloop.cpp:204
#78 0x00007f5d2cfc77db in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#79 0x000000000041b7ee in main (argc=1, argv=0x7fffaf5559f8) at /var/tmp/portage/kde-base/blogilo-4.7.95/work/blogilo-4.7.95/blogilo/src/main.cpp:59

Still happens with KDE 4.8 RC2.

I have found the problem. Bad CFLAGS set for compilation of qt-webkit. So move along.