How to debug crash in qt5core.dll thread
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@Dariusz said in How to debug crash in qt5core.dll thread:
I've been trying build qt from source today.
Why?
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Hello
@Christian-Ehrlicher I've been trying build qt from source today... following readme as much as I could... so far I had some "limited" success but I got stuck mid compile... Here are my steps :
CMD WITH AMIN cd C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build vcvarsall.bat x86_amd64 cd C:\Qt\5.15.1\Src\qtbase configure -debug-and-release -opengl desktop -nomake -opensource -platform win32-msvcIt starts doints its "Magic" but some work in I get this >
cl -Yuqmake_pch.h -FIqmake_pch.h -Fpqmake_pch.pch -c -Fo./ -Fdqmake.pdb -W2 -nologo -O2 /MP /wd4577 -IC:\Qt\5.15.1\Src\qtbase\qmake -IC:\Qt\5.15.1\Src\qtbase\qmake\library -IC:\Qt\5.15.1\Src\qtbase\qmake\generators -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\unix -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\win32 -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\mac -IC:\Qt\5.15.1\Src\qtbase/src/3rdparty/tinycbor/src -IC:\Qt\5.15.1\Src\qtbase/include -IC:\Qt\5.15.1\Src\qtbase/include\QtCore -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1 -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1\QtCore -I..\src\corelib\global -IC:\Qt\5.15.1\Src\qtbase\mkspecs\win32-msvc -D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS -DQT_VERSION_STR=\"5.15.1\" -DQT_VERSION_MAJOR=5 -DQT_VERSION_MINOR=15 -DQT_VERSION_PATCH=1 -DQT_BUILD_QMAKE -DQT_BOOTSTRAPPED -DPROEVALUATOR_FULL -DQT_NO_FOREACH -DUNICODE -D_ENABLE_EXTENDED_ALIGNED_STORAGE C:\Qt\5.15.1\Src\qtbase\src\corelib\serialization\qjsonobject.cpp qjsonobject.cpp cl -c -Fo./ -Fdqmake.pdb -W2 -nologo -O2 /MP /wd4577 -IC:\Qt\5.15.1\Src\qtbase\qmake -IC:\Qt\5.15.1\Src\qtbase\qmake\library -IC:\Qt\5.15.1\Src\qtbase\qmake\generators -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\unix -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\win32 -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\mac -IC:\Qt\5.15.1\Src\qtbase/src/3rdparty/tinycbor/src -IC:\Qt\5.15.1\Src\qtbase/include -IC:\Qt\5.15.1\Src\qtbase/include\QtCore -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1 -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1\QtCore -I..\src\corelib\global -IC:\Qt\5.15.1\Src\qtbase\mkspecs\win32-msvc -D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS -DQT_VERSION_STR=\"5.15.1\" -DQT_VERSION_MAJOR=5 -DQT_VERSION_MINOR=15 -DQT_VERSION_PATCH=1 -DQT_BUILD_QMAKE -DQT_BOOTSTRAPPED -DPROEVALUATOR_FULL -DQT_NO_FOREACH -DUNICODE -D_ENABLE_EXTENDED_ALIGNED_STORAGE -DQT_BUILD_QMAKE_BOOTSTRAP C:\Qt\5.15.1\Src\qtbase\src\corelib\global\qlibraryinfo.cpp cl -Yuqmake_pch.h -FIqmake_pch.h -Fpqmake_pch.pch -c -Fo./ -Fdqmake.pdb -W2 -nologo -O2 /MP /wd4577 -IC:\Qt\5.15.1\Src\qtbase\qmake -IC:\Qt\5.15.1\Src\qtbase\qmake\library -IC:\Qt\5.15.1\Src\qtbase\qmake\generators -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\unix -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\win32 -IC:\Qt\5.15.1\Src\qtbase\qmake\generators\mac -IC:\Qt\5.15.1\Src\qtbase/src/3rdparty/tinycbor/src -IC:\Qt\5.15.1\Src\qtbase/include -IC:\Qt\5.15.1\Src\qtbase/include\QtCore -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1 -IC:\Qt\5.15.1\Src\qtbase/include\QtCore\5.15.1\QtCore -I..\src\corelib\global -IC:\Qt\5.15.1\Src\qtbase\mkspecs\win32-msvc -D_CRT_SECURE_NO_WARNINGS -D_SCL_SECURE_NO_WARNINGS -DQT_VERSION_STR=\"5.15.1\" -DQT_VERSION_MAJOR=5 -DQT_VERSION_MINOR=15 -DQT_VERSION_PATCH=1 -DQT_BUILD_QMAKE -DQT_BOOTSTRAPPED -DPROEVALUATOR_FULL -DQT_NO_FOREACH -DUNICODE -D_ENABLE_EXTENDED_ALIGNED_STORAGE C:\Qt\5.15.1\Src\qtbase\src\corelib\serialization\qjsonvalue.cpp qjsonvalue.cpp qlibraryinfo.cpp link /OUT:..\bin\qmake.exe project.obj main.obj ioutils.obj proitems.obj qmakevfs.obj qmakeglobals.obj qmakeparser.obj qmakeevaluator.obj qmakebuiltins.obj makefile.obj unixmake.obj unixmake2.obj mingw_make.obj option.obj winmakefile.obj projectgenerator.obj property.obj meta.obj makefiledeps.obj metamakefile.obj xmloutput.obj msvc_nmake.obj msvc_vcproj.obj msvc_vcxproj.obj msvc_objectmodel.obj msbuild_objectmodel.obj registry.obj qbitarray.obj qbuffer.obj qcryptographichash.obj qfilesystementry.obj qfilesystemengine.obj qfilesystemengine_win.obj qfilesystemiterator_win.obj qfsfileengine.obj qfsfileengine_iterator.obj qarraydata.obj qbytearray.obj qbytearraylist.obj qvsnprintf.obj qbytearraymatcher.obj qcalendar.obj qdatetime.obj qdir.obj qdiriterator.obj qfiledevice.obj qfile.obj qtemporaryfile.obj qabstractfileengine.obj qfsfileengine_win.obj qsystemlibrary.obj qfileinfo.obj qendian.obj qglobal.obj qgregoriancalendar.obj qhash.obj qiodevice.obj qringbuffer.obj qdebug.obj qlist.obj qlocale.obj qlocale_tools.obj qlocale_win.obj qversionnumber.obj qmalloc.obj qmap.obj qoperatingsystemversion.obj qoperatingsystemversion_win.obj qregexp.obj qromancalendar.obj qutfcodec.obj qstring.obj qstringlist.obj qstringbuilder.obj qsystemerror.obj qtextstream.obj qdatastream.obj quuid.obj qrandom.obj qsettings.obj qvariant.obj qsettings_win.obj qmetatype.obj qxmlstream.obj qxmlutils.obj qnumeric.obj qlogging.obj qcborstreamwriter.obj qcborvalue.obj qjsoncbor.obj qjsondocument.obj qjsonparser.obj qjsonarray.obj qjsonobject.obj qjsonvalue.obj qlibraryinfo.obj qmake_pch.obj ole32.lib advapi32.lib shell32.lib netapi32.lib Microsoft (R) Incremental Linker Version 14.27.29112.0 Copyright (C) Microsoft Corporation. All rights reserved. Info: creating cache file C:\Qt\5.15.1\Src\qtbase\.qmake.cache ERROR: No value supplied to command line option 'nomake'.Any ideas how to bite it? I'm lost o.o
I tried running it again now and all I get is the error above without any progress... just Boostrapping qmake... jom1.1.3 & error
@Dariusz
All @Christian-Ehrlicher asked you to do was:Install the debug information and source with the Qt online installer and build / run your program in debug.
By downloading just that stuff your PC will have more information to show you in the debugger when inside Qt libraries. It just needs these files to be found, it does not mean you need to build Qt yourself. Assuming you download files from the same version of Qt as you previously installed.
But btw you may not even have needed to do this. If you claim you have a "crash in qt5core.dll", start by running your app from witihin the debugger. When it "crashes" the debugger should break. Find the stack trace window pane. If you have compiled your own code for debug, it will hopefully show you a trace back into some particular line of your own source. That may be all you need to diagnose the cause, without requiring Qt library symbols/source.
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@Christian-Ehrlicher said in How to debug crash in qt5core.dll thread:
@Dariusz said in How to debug crash in qt5core.dll thread:
I've been trying build qt from source today.
Why?
I though thats what u meant... to build debug dlls from source to use in my debug app to debug issue.
@JonB said in How to debug crash in qt5core.dll thread:
@Dariusz
All @Christian-Ehrlicher asked you to do was:Install the debug information and source with the Qt online installer and build / run your program in debug.
By downloading just that stuff your PC will have more information to show you in the debugger when inside Qt libraries. It just needs these files to be found, it does not mean you need to build Qt yourself. Assuming you download files from the same version of Qt as you previously installed.
But btw you may not even have needed to do this. If you claim you have a "crash in qt5core.dll", start by running your app from witihin the debugger. When it "crashes" the debugger should break. Find the stack trace window pane. If you have compiled your own code for debug, it will hopefully show you a trace back into some particular line of your own source. That may be all you need to diagnose the cause, without requiring Qt library symbols/source.
Yes when I run in debug I have stack trace... and it starts on my app, few function down the line it dives in to Qt dlls and dies there. So I don't really know what/why/where it "really" dies.
Its threading error. I just cant fully debug it as half of the error happens on Qt side.
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@Dariusz said in How to debug crash in qt5core.dll thread:
few function down the line it dives in to Qt dlls and dies there.
So you should take a look in your code where you call the Qt function which crashes to see if there is something wrong.
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@Dariusz said in How to debug crash in qt5core.dll thread:
few function down the line it dives in to Qt dlls and dies there.
So you should take a look in your code where you call the Qt function which crashes to see if there is something wrong.
@Christian-Ehrlicher said in How to debug crash in qt5core.dll thread:
@Dariusz said in How to debug crash in qt5core.dll thread:
few function down the line it dives in to Qt dlls and dies there.
So you should take a look in your code where you call the Qt function which crashes to see if there is something wrong.
Well it does not crash in my code. It gets a request from my code to set a widget and then it crashes in internal Qt logic. So I cant debug it can I? The only way is to to get stack from qt dlls and see which thread/ptr/item cause issue and figure out why. I take there is a threading problem but I need more info to narrow it down.
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So did you finally have a valid backtrace as we suggested already many times?
Simplify your code until it no longer crashes. -
@Christian-Ehrlicher Yes I've installed extra modules from QT... I still don't have valid trace. This is all I get >
When I break stop start of the app and step by step all the way to
return a.exec();There is no crash. The second I hit a.exec() I get a crash. Hell I even see qt widget for a split second with all data populated properly and then it kicks the bucket.So yea, nope I need to see function, location, data etc etc >
I'm still stuck trying to compile the source. :- (
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After you install the sources and debug info files, you need to set source paths mapping and add CDB symbol paths in the options dialog to make them work in debugging by Qt Creator.
If you are using visual studio, I'm not sure if you can map the sources but you should also add the symbol path.
There's really no need to compile Qt from source. -
After you install the sources and debug info files, you need to set source paths mapping and add CDB symbol paths in the options dialog to make them work in debugging by Qt Creator.
If you are using visual studio, I'm not sure if you can map the sources but you should also add the symbol path.
There's really no need to compile Qt from source.@Bonnie Hey, thanks for info! But I'm lost, what paths, to what files ? above all where ? o.o
I went to https://doc.qt.io/qtcreator/creator-debugger-engines.html but I did not find anything about symbols
I've no idea where qt has downloaded the Qt Debug information files :- ( -
@Bonnie Hey, thanks for info! But I'm lost, what paths, to what files ? above all where ? o.o
I went to https://doc.qt.io/qtcreator/creator-debugger-engines.html but I did not find anything about symbols
I've no idea where qt has downloaded the Qt Debug information files :- (@Dariusz
It's quite simple if your are using Qt creator to debug.
In "Source Paths Mapping" of the General tab, click "Add Qt sources..." and choose the Src folder.
Then in "Symbol Paths" of the CDB Paths tab, click "Insert..." and choose the Qt bin folder (that's usually the .pdb files are downloaded to).
