Qt5 can not start application out of the IDE - qt

I'm working on a program with Qt 5.5 in the IDE Qt Creator 3.4.2 (Community). The program can be started normally in the IDE, but when I try to double-click the .exe file, it says
Cannot find the entry point for the procedure __cxa_throw_bad_array_new_length in library D:\Qt\5.5\mingw492_32\bin\Qt5Test.dll
and
Cannot find the entry point for the procedure __cxa_throw_bad_array_new_length in library D:\Qt\5.5\mingw492_32\bin\Qt5Core.dll
I have added
D:\Qt\Tools\mingw492_32\bin;D:\Qt\5.5\mingw492_32\bin;
to my environmental variable.
Any ideas about what's wrong?

I think currently your program is using dlls from the folders:
D:\Qt\Tools\mingw492_32\bin;D:\Qt\5.5\mingw492_32\bin;
And the correct one is:
D:\Qt\Qt5.5\Tools\QtCreator\bin\
(Make sure it is correct on your machine)
This is the one Qt Creator is using. You need to add it to PATH before mingw path or copy dlls you need from it to your folder with your exe.

Actually, libstdc++-6.dll is needed

Related

Build Qt projects using static build

I have created a program in Qt using Qt Creator. When I open it, the message appears "The program can't start because Qt5Cored.dll and Qt5widgetsx.dll is missing from your computer. Try reinstalling the program to fix this problem."
copy required libraries from you Qt installation to the directory of executable.
Have you really got a static compiled version of Qt? and are you statically compiling your project?... if so your output executable will be around 30-40mb.... and it won't be asking you for dlls.
However it looks like you have a dynamically linked output, in which case you need to find all the DLLs that your projects uses. You can get these from the folder:
<installpath>\Qt\5.5\mingw492_32\bin for example (different if you use linux / msvc)
Keep running the program and grab each dll it complains about... or use somthing like dependency walker (a free executable you can find online) to help determine which DLLs you need.
You probably need (For windows, using mingw):
Qt5Widgets.dll
Qt5Gui.dll
Qt5Core.dll
libwinpthread-1.dll
libstdc++-6.dll
libgcc_s_dw2-1.dll
Or the debug version in your case which end in "d" e.g.: Qt5Core.dll (release), Qt5Cored.dll (debug). Note versions may be different for your installation version. Copy these files next to your executable. OR include <installpath>\Qt\5.5\mingw492_32\bin in your path.
You need to add all the required dlls
C:\Qt\5.2.1\mingw48_32\bin\
to your project. https://forum.qt.io/topic/50705/solved-qt3d-executable-error-qt5cored-dll-is-missing-from-your-computer/2 should solve your problem.

static linking of standard QT libraries

I am trying to build an QT application with version 5.4.
and when ever I am trying to run the exe on a different machine where QT is not installed I am getting below error "The program cannot start because QT5core.dll is missing from your computer, Try reinstalling the program to fix this problem".
and when I copied QT5core.dll with the exe in a machine where QT is not installed its working fine.
Is there any way that I can link QT5core.dll with the exe statically so that whatever place I run this exe it should not ask for any dll.
Thanks,
Tushar
You can build a standalone version of your Qt application so that it doesn't have any library dependencies at runtime. Be warned though: this can greatly expand the size of the .exe generated and the compilation time. Have a look here:
https://wiki.qt.io/Build_Standalone_Qt_Application_for_Windows
and here:
https://wiki.qt.io/How_to_build_a_static_Qt_version_for_Windows_with_gcc

Error in OpenCV configuration for Qt Creator

I followed these instructions in the configuration of OpenCV SDK for using it in Qt Creator IDE, but I couldn't conclude point 6.5, due to configuration errors in Cmake-GUI. I setup the configuration in CMake of the compilers gcc and g++ contained in Qt folder for MinGW32, and all looks Ok. But when Cmake-GUI starts the process of build configuration it ends up saying
"Error in configuration process, project files may be invalid".
It can't find the following:
QT_QMAKE_EXECUTABLE;
Qt5Concurrent_DIR;
QT5Core_DIR;
QT5Gui_DIR;
QT5Test_DIR;
QT5Widgets_DIR.
After this issue I tried to go on with following points of configuration tutorial, without reaching the final instruction of mingw32-make install. I'm using the following versions of softwares: Qt 5.3.0, OpenCV 2.4.9, CMake 2.8.12.2. My OS is Windows 7.
How can I recover the missing Qt files in CMake configuration?
Is there an alternative way for configuring OpenCV with Qt (like using precompiled build of OpenCV libraries)?
You just need to indicate CMake the correct paths to each one. Click oh the path to browse and set each one individually:
QT_QMAKE_EXECUTABLE;
For this one, you need to search inside the Qt installation folder for the /bin directory. On it, you' ll find the qmake.exe. In my case it was C:/Qt/5.3/winrt_x64/bin/qmake.exe
All the following ones are in the Qt's /lib/cmake directory. In my case: C:/Qt/5.3/winrt_x64/lib/cmake :
Qt5Concurrent_DIR;
C:/Qt/5.3/winrt_x64/lib/cmake/Qt5Concurrent
QT5Core_DIR;
C:/Qt/5.3/winrt_x64/lib/cmake/Qt5Core
QT5Gui_DIR;
C:/Qt/5.3/winrt_x64/lib/cmake/Qt5Gui
QT5Test_DIR;
C:/Qt/5.3/winrt_x64/lib/cmake/Qt5Test
QT5Widgets_DIR.
C:/Qt/5.3/winrt_x64/lib/cmake/Qt5Widgets
Then click generate. It' ll show a new error and ask you for the QT5OpenGL_DIR. Just as before, show CMake the correct directory. In my case: C:/Qt/5.3/winrt_x64/lib/cmake/Qt5OpenGL. Finally, click Configure again, and then Generate, and now you're done creating the build files.
You have to specify the location of Qt manually by passing it as an argument for QT5Core_DIR. Qt5_DIR or CMAKE_PREFIX_PATH does also the trick.
Example
Given your Qt 5 is installed at /opt/selfcompiled/Qt5. When calling cmake, add the flag from above:
cmake -DQt5_DIR=/opt/selfcompiled/Qt5 <pathToSourceDir>
Once the Qt 5 directory is set and found by CMake, all the other variables related to Qt 5 should be found from there, too.

.exe not running through QtCreator and from outside in Qt 4.8.1. issues regarding dll

I have Qt 4.8.1 installed on a windows 7 64 bit OS. I am using opencv and Qt together for my project.
For opencv dll's i gave the necessary path and everything in .pro. Everything was working fine until yesterday.
My code gets compiled successfully, but now when i run, it says that abc.exe executed with code -1073741511.
When I manually run the .exe file from debug or release folder it says that some entry point could not be located in QtCore4.dll.
I tried everything, from setting the Qt & opencv Dlls in %PATH% environment variable to copy and pasting the dlls to the same folder to that of .exe
i hav seen the .exe through dependency walker also and it shows me red color in Link checksum field of QtCore4.dll.
Can anybody help me on this?????
Make sure you are not using (by using i mean copy/add to path) a wrong dll, i mean a dll that was built with a different compiler, example the default (MinGW version) SDK has two versions of QtCore.dll: the correct one (built with MinGW): QT_INSTALL_PATH/qt/bin and one built with some version of VS: QT_INSTALL_PATH/bin (this one is used by Creator and other tools)

Hardcoded QMAKESPEC in Qt Creator?

I installed Qt SDK (Qt framework + Qt Creator) but didn't like the layout of folders so I deleted it (without uninstalling), moved framework in one place and Qt Creator in another and installed Qt framework and Qt Creator separately placing each over the respective old one.
The problem is Qt Creator in Projects/Build Settings/Build Steps keeps showing the old path to the specification file:
-spec c:/qt/2009.03/qt/mkspecs/win32-g++
Setting QMAKESPEC environment variable either in the system or in Projects/Build Environment doesn't change anything.
How can I force Qt Creator to see and use new location of the specification file?
This does not fully solve the issue but if you add '-spec' (without quotes) in the additional arguments box in build steps -> qmake, then it removes the win32-g++ argument.
NOTE: I have NOT been able to build the project after doing this (i changed it to win32-icc and win32-msvc2008 as i have both the intel c++ compiler and VS2008) but the build fails with the error ---- "*** MIssing Separator. Stop." in the makefile
I don't have Qt Creator installed, but I suppose it may store this setting somewhere on filesystem, look in your %HOME% or %APPDATA% for directories associated with Qt Creator and search the files inside for this path.
Have you tried going into Projects->Build Settings->General and clicking on the "Manage Qt Versions" and making sure that everything there is all correct?

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