Using wrapped Qt segfaults on Linux with only a basic example - c

Question

I've been experimenting with wrapping some Qt classes with a C interface to use with my latest D project. For what ever reason, this code works fine on Windows but segfaults on Linux and I haven't been able to track down the reason behind it. I haven't tried building on OSX yet.
I'm using Qt 5.3, and running Linux Mint.
The code is kind of spread out over a few different files so I thought it might be easier if I put all the related code into some pastebins.
QApplication Wrapper Stuff
QMainWindow Wrapper Stuff
These are very thin wrappers though, so even if you don't look at them it should be easy enough to understand my test program.
#include <Application.h>
#include <MainWindow.h>
int main( int argc, char* argv[])
{
Qt_Application* app = Qt_Application_create(argc, argv);
Qt_MainWindow* window = Qt_MainWindow_create();
Qt_MainWindow_show(window);//<- Segfault happens here
Qt_Application_exec(app);
Qt_Application_destroy(app);
Qt_MainWindow_destroy(window);
return 0;
}
Due to some printf tests, I know the segfault happens on when I try to call Qt_MainWindow_show, and likewise I know the window object exists when I pass it so that isn't the cause. Also, if I comment Qt_MainWindow_show out, Qt_Application_exec will get called no problem so as far as I know the wrapped objects are being created correctly.
When I run gdb, it says:
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff789a92a in strlen () from /lib/x86_64-linux-gnu/libc.so.6
getting the backtrace at the point of the segfault shows this:
#0 0x00007ffff789a92a in strlen () from /lib/x86_64-linux-gnu/libc.so.6
#1 0x00007ffff6b6c6bc in QCoreApplication::arguments() ()
from /home/jebbs/Qt/5.3/gcc_64/lib/libQt5Core.so.5
#2 0x00007ffff1470213 in ?? ()
from /home/jebbs/Qt/5.3/gcc_64/plugins/platforms/libqxcb.so
#3 0x00007ffff14705f9 in ?? ()
from /home/jebbs/Qt/5.3/gcc_64/plugins/platforms/libqxcb.so
#4 0x00007ffff147d127 in ?? ()
from /home/jebbs/Qt/5.3/gcc_64/plugins/platforms/libqxcb.so
#5 0x00007ffff1470009 in ?? ()
from /home/jebbs/Qt/5.3/gcc_64/plugins/platforms/libqxcb.so
#6 0x00007ffff5d47e03 in QWindow::create() ()
from /home/jebbs/Qt/5.3/gcc_64/lib/libQt5Gui.so.5
#7 0x00007ffff716b97a in QWidgetPrivate::create_sys(unsigned long long, bool, bool) () from /home/jebbs/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5
#8 0x00007ffff714e6f5 in QWidget::create(unsigned long long, bool, bool) ()
from /home/jebbs/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5
#9 0x00007ffff71512ea in QWidget::setVisible(bool) ()
from /home/jebbs/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5
#10 0x00007ffff7bd8205 in Qt_MainWindow_show ()
from /home/jebbs/Documents/projects/HeliosCTest/libqtcl.so.1
#11 0x0000000000400922 in main (argc=1, argv=0x7fffffffe158) at main.cpp:22 <-actually points to Qt_MainWindow_show(window), but this is from a test with printf's in it
So it looks like some string somewhere is NULL and strlen cries? I couldn't find any reason that QMainWindow.show() might segfault. Any pointers into where I should look or what I should do next would be an excellent help.