attempt at using node-ffi, but node-ffi cannot find the symbols

main.cpp

#include <stdint.h>
#include <QtCore/QtGlobal>
 
#if defined(MYSHAREDLIB_LIBRARY)
#  define MYSHAREDLIB_EXPORT Q_DECL_EXPORT
#else
#  define MYSHAREDLIB_EXPORT Q_DECL_IMPORT
#endif

MYSHAREDLIB_EXPORT uint64_t factorial(int max) {
    int i           = max;
    uint64_t result = 1;
    
    while (i >= 2)
        result *= i--;
    
    return result;
}

stackoverflow.js

var FFI = require('node-ffi')
	,libstackoverflow = new FFI.Library("build/libstackoverflow", {
		'factorial': [ 'uint64', [ 'int' ] ]
	});
	
console.log(libstackoverflow.factorial(10));

stackoverflow.pro

######################################################################
# Automatically generated by qmake (2.01a) Wed Jun 8 21:28:16 2011
######################################################################

TEMPLATE = lib
DEFINES += MYSHAREDLIB_LIBRARY
CONFIG += qt dll
TARGET = 
DEPENDPATH += .
INCLUDEPATH += .
DESTDIR = ./build

# Input
SOURCES += main.cpp