I stumbled across the build system meson ( http://mesonbuild.com/ ) which attracted me due to its simplicity and native Qt support.
However, when I followed the tutorial I got the error message
Build type: native build
Project name: qt5 demo
Native cpp compiler: c++ (clang 8.1.0)
Build machine cpu family: x86_64
Build machine cpu: x86_64
Found pkg-config: /usr/local/bin/pkg-config (0.29.2)
Dependency QtWidgets found: NO
Meson encountered an error in file meson.build, line 3, column 0:
Qt5 native dependency not found (checked pkg-config, qmake-qt5, and qmake)
which is weird because when I use Qt Creator I can create, compile, and execute Qt projects easily. I am using MacOS Sierra.
Can I somehow tell meson where qmake is located?
Ok, I fixed this issue by adding
export PATH="<path to qmake>":$PATH
to my .bash_profile file, where is the path to the folder containing the qt binaries, such as qmake.
Related
I'm trying to compile and run an application on a MacBook using Qt Creator. There are no issues compiling the project, but when I try and run it, it seems to be unable to load a plugin.
Could not load the Qt platform plugin "cocoa" in "" even though it was found.
The application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
This error occurs both when trying to run the application from Qt Creator or via Finder. It seems to only happen when I use the CMake build system (no issues when using QMake), but my existing project that I need to deploy on MacOS uses CMake.
My steps to reproduce are:
Install a completely clean MacOS (no user data)
Install Xcode 11
Install CMake 3.15
Install Qt 5.13.1 MacOS package
Open QtCreator->New Project->Qt Quick Application - Scroll
Set build system to CMake (important)
Compile and notice error
I am using:
Qt 5.13.1
macOS Catalina 10.15
Apple Clang 11
I recognize that for final user deployment I will need to use the macqtdeploy tool to copy the Qt libraries to the executable folder, but I should be able to run my app from QtCreator without doing this? Especially as it works fine when using QMake.
So it ended up being some kind of name resolution thing where Qt Creator couldn't decide whether to use the debug or release versions of the framework. Supplying DYLD_IMAGE_SUFFIX=_debug fixed this (add this to the environment section under Kits).
I have Qt 5.5.1 custom build (cross compiled on x86 for ARM development). So the project is building on x86 host and then deployed to Jetson TK1 development board.
I have the error:
Project ERROR: Unknown module(s) in QT: serialport
I can see build library: /home/alan/work/qt/qt-everywhere-opensource-src-5.5.1/qtserialport/lib/libQt5SerialPort.so.5.5.1, source and header files for QtSerialPort module in qt build directory. So I think the module is build but not properly installed. Never deal with custom Qt modules so how to check if module build and installed correctly?
Update: Qt was build but was not installed into OS (Qt Creator allows to use such builds to creating kits).
Modules only available after install. Another option - link module as separate library.
I am trying to install Jom (http://wiki.qt.io/Jom) for C++. When I type in qmake -r in cmd, I get the error Project MESSAGE: Cannot build jom with Qt version 4.8.7. Project ERROR: Use at least Qt 5.2.0.. This is because I have PyQt version 4.8.7 and Qt version 5.8.0 both installed. When building Jom, Jom searches for in the wrong Qt folder. How can I fix this?
If you have multiple version of Qt installed, you also have multiple version of qmake. You can check which qmake you are running by using where qmake on Windows, it will output a list of qmake executable available in your path, the first one in the list will be the one executed when running qmake.
For instance:
C:\>where qmake
C:\Qt\5.8\msvc2015\bin\qmake.exe
C:\Qt\5.6\msvc2015\bin\qmake.exe
If the first one, is not the one you want, you can run it by using its complete path:
C:\>C:\Qt\5.6\msvc2015\bin\qmake.exe -version
QMake version 3.0
Using Qt version 5.6.2 in C:/Qt/5.6/msvc2015/lib
If the qmake and Qt version you want is not in your PATH, you can use the scripts provided by Qt to setup a valid environment. These are available in the Start menu as Qt 5.8 64-bit for Desktop (MSVC 2015) (change according to your installation), or you can use them directly by executing qtenv2.bat (e.g C:\Qt\5.8\msvc2015\bin\qtenv2.bat).
If you are using MinGW you are all set, but if you are using MSVC you need also to run vcvarsall.bat, which can be found in your Visual installation folder.
Because I am not a Java enthusiast, I decided to use C++ and Qt for one of my projects. However, I came across the big cross-compiling Qt problem, and I am unable to produce an .exe file for Windows users.
My setup
Linux Ubuntu 12.04, with Wine and Qt. qmake -v gives the following output :
QMake version 2.01a
Using Qt version 4.8.1 in /usr/lib/x86_64-linux-gnu
I also have a MinGW32 compiler, which can be found at /usr/bin/i586-mingw32msvc-g++. My Wine drive_c folder contains the following Qt directories :
$HOME/.wine/drive_c/Qt/Qt5.2.0/5.2.0/Src
$HOME/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32
The mingw48_32 directory contains the necessary include/ and lib/ directories, which are used in my mkspec file, /usr/share/qt4/mkspecs/win32-x-g++/qmake.conf :
QMAKE_INCDIR_QT = /home/me/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32/include
QMAKE_LIBDIR_QT = /home/me/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32/lib
The problem
According to most guides I've found about Qt cross-compiling, my setup should be enough to run a simple :
qmake -spec win32-x-g++
make
wine /path/to/my/application.exe
But... nothing's linked. QApplication and every other symbol I use in my program are "not found". No QApplication, no QPushButton, no connect(), no SIGNAL(), no SLOT()...
My objective here is to successfully configure QtCreator to use this setup (in an independent build configuration), so that it can build a Linux executable (through the first and working configuration), and a Win32 .exe (through the MinGW setup above). However, I cannot modify a single build step in QtCreator :
Cannot add a "MinGW" toolchain : it is not available in the "Add" dropdown list.
Cannot change the -spec parameter value in the project build configurations panel. The field is non-editable.
Despite guides and solutions I found all over the Internet, my only solution so far is to send my source code to a virtual Windows machine, and have it create a new project with it. On this VM, I could probably compile for Windows... But of course, this doesn't actually sound like a real "solution" to me...
Is there any way Qt(Creator) has finally made cross-compiling easier now ? I'm getting a bit tired of "symbol not found" errors...
First,
sudo apt-get install mingw-w64
Then, check if Qt Creator finds the toolchain.
Next, until Ubuntu starts providing a mingw-w64-qt package, download the Qt source and build it. This is bound to get messy, and maybe even the simplest thing to do is to install WINE and use a Windows Qt version.
I've downloaded Qt 4.8.2 library, Qt Creator 2.5.2, and manually installed MingW with w32api version 3.13 and GCC/g++ version 4.7.0.1. My OS is Windows 7 Ultimate x64.
I can create a sample "Plain C++ project" in Qt Creator; compile and run that console application using g++ without any issue.
But I cannot run a Qt application. I used Qt Creator, created a dummy Qt Application using Creator's "Qt Gui Application" template. The project can be compiled successfully, without any error or warning. But the binary keeps crashing when I try to run (both from Qt Creator and Windows Explorer) it. Both debug and release builds crash. It crashes even before showing main window.
MingW is installed in C:\MingW and C:\MingW\bin is in PATH. Qt is installed in C:\Qt\4.8.2 and C:\Qt\4.8.2\bin is in PATH.
I analyzed generated exe of the Qt Gui Application output with Dependency Walker and found that it found all required DLLs:
c:\windows\system32\KERNEL32.DLL
c:\windows\system32\MSVCRT.DLL
c:\mingw\bin\LIBGCC_S_DW2-1.DLL
c:\mingw\bin\LIBSTDC++-6.DLL
c:\qt\4.8.2\bin\QTCORE4.DLL
c:\qt\4.8.2\bin\QTGUI4.DLL
So, what's causing the runtime crash?
EDIT
I also tried Qt's example projects: 2dpainting and addressbook - both crashed when they were launched.
You should build Qt with the MinGW compiler you're using to build your application. GCC is generally less sensitive to binary compatibility issues than MSVC is, but Qt is a big, complex framework library. If anything would expose those kinds of issues, Qt would probably be on the short list.
Building Qt is pretty straightforward, but it takes a lot of time and there always seems to be two or three patches I need to make to get things to build successfully.
The last time I built Qt (4.7.3) with MinGW, I had to make the following patches - I'm not sure whether they will still apply to Qt 4.8:
make sure not to enable C++11 mode in the compiler - there are several macros with concatenated string literals that break under the new C++11 extended literal syntax
there is a problem with how some distributions of MinGW incorporate the Microsoft extensions to float.h - I had to sometimes had to add the line:
#include_next <float.h>
to the end of the MinGW-specific float.h so the generic GCC float.h would get processed properly. I had to do this for nuwen 4.7.0 lib/gcc/i686-pc-mingw32/4.7.0/include/float.h and TDM 4.6.1 32-bit distro lib/gcc/mingw32/4.6.1/include/float.h (the 64-bit distro of TDM didn't need this patch).
patch qmake\Makefile.win32-g++ and qmake\Makefile.win32-g++-sh to remove the -static-libstdc++ option that GCC doesn't recognize (and now errors out on instead of ignores)
patch mkspecs/win32-g++/qmake.conf to move the -Wl, in the QMAKE_LFLAGS_EXCEPTIONS_ON macro to its proper place in QMAKE_FLAGS:
QMAKE_LFLAGS = -Wl,-enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc
QMAKE_LFLAGS_EXCEPTIONS_ON = -mthreads
copy make.exe to mingw32-make.exe in MinGW's bin directory if there's not already a mingw32-make.exe
Then building Qt consists of:
set QTDIR=<location of Qt source directory> # where configure.exe is
set PATH=%QTDIR%\bin;c:\MinGW\bin;%PATH%
set INCLUDE=
set LIB=
cd %QTDIR%
mingw32-make confclean # (this should fail the first time, since there's nothing to clean)
configure.exe -opensource -debug-and-release -nomake examples -nomake demos -nomake tests -platform win32-g++ # and accept the GPL license
mingw32-make
This takes a while... hopefully nothing else will need patching.
I also got this problem. I'm a Qt n00b and tought, when installing Qt-libraries, that "well I already have Mingw installed so I skip installing the Mingw that comes with Qt". That gave me prolems. When installing mingw that came with Qt everything worked ok.
So my advice to anyone googling to this question (like I did) is to instead of using your already installed Mingw, install the one with Qt and use that (otherwise you have to build the Qt libraries within your Mingw, like the answer from Michael Burr)