Setting compiler right for meson - c++

Question

I am trying to build a basic Qt Application with the Meson Build System on my Mac (using macOS Sierra), following the tutorial on http://mesonbuild.com/samples.html.
My meson.build file looks like this:
project('qt5 demo', 'cpp',
default_options : ['cpp_std=c++11'])
qt5_dep = dependency('qt5', modules : ['Core', 'Gui', 'Widgets'])
# Import the extension module that knows how
# to invoke Qt tools.
qt5 = import('qt5')
prep = qt5.preprocess(moc_headers : 'mainWindow.h',
ui_files : 'mainWindow.ui')
executable('qt5app',
sources : ['main.cpp', 'mainWindow.cpp', prep],
dependencies : qt5_dep,
cpp_args : '-std=c++11')
I have a small test program consisting of only four files: main.cpp, mainwindow.h, mainwindow.cpp, and mainwindow.ui.
The source code is as follows.
main.cpp:
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
mainwindow.h:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainWindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
The program compiles and executes as expected when I use qmake as a build system using the following qmake-file:
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = QtDesigner
TEMPLATE = app
SOURCES += main.cpp\
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
When I execute
meson build
it works fine, except for the warning:
WARNING: rcc dependencies will not work reliably until this upstream issue is fixed:
https://bugreports.qt.io/browse/QTBUG-45460
It also compiles without errors, when I switch to the build directory and call
ninja
but when I execute the program I get the following error:
dyld: Library not loaded: #rpath/QtCore.framework/Versions/5/QtCore
Referenced from:
/Users/<myname>/code/C++/QtDesignerCode/build/./qt5app
Reason: image not found
Abort trap: 6
It seems like the linker cannot find the libraries? Which is weird, as in Qt Creator (using qmake) the source code compiles fine.
Thanks in advance for any help.

Answer 1

Do the following in the build dir
mesonconf -Dcpp_std=c++11
or, set the default language version in your meson.build file