qt creator defaults to g++ (4.2) after specifying custom GCC - macos

Question

Problem
I am having an issue implementing the g++48 compiler in QT Creator. I built this compiler using MacPorts. It appears that QT Creator ignores my compiler and defaults xcode g++42. How do I properly setup the compiler to override this?
Troubleshooting
Did you install gcc/g++ correctly and is it the main one selected?
I have ensured that gcc was installed correctly and the path is correct by doing the follows:
:~ which gcc:
/opt/local/bin/g++
:~ g++ --version:
g++ (MacPorts gcc48 4.8.1_3) 4.8.1
What system are you using?
My system: Mac OSX 10.9 Mavericks. QT Creator 2.8.1 Based on QT 5.1.0.
Toolchain setup: In QT Creator I specified the custom GCC compiler by going Compilers_Add_GCC and putting in the compiler path /opt/local/bin/g++. If I hover the mouse over any of the #include lines in *.cpp then it properly displays the path /opt/local/include/gcc48/{headerName}. I suspect the problem is related to the QT Mkspecs, but I really don't understand what this is or how to write a custom one for my custom gcc installation (if necessary). Can this be explained?
Kit updated in QT Creator? The kit was updated by following the directions that here: Qt Creator use another GCC Version located in another Place
Why do you suspect g++42 is being used? This is based on the results I get from inspecting the build log file.
12:30:19: Running steps for project untitled...
12:30:19: Configuration unchanged, skipping qmake step.
12:30:19: Starting: "/usr/bin/make"
/Applications/Xcode.app/Contents/Developer/usr/bin/g++ -c -pipe -std=c++11 -g -gdwarf-2 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -mmacosx-version-min=10.6 -Wall -W -fPIE -DQT_QML_DEBUG -DQT_DECLARATIVE_DEBUG -I/Users/raymondvaldes/Qt/5.1.0/clang_64/mkspecs/macx-g++ -I/Users/raymondvaldes/Documents/code/untitled -I. -o main.o /Users/raymondvaldes/Documents/code/untitled/main.cpp
/Users/raymondvaldes/Documents/code/untitled/main.cpp:4:10: fatal error: 'random' file not found
#include <random>
^
1 error generated.
make: *** [main.o] Error 1
12:30:20: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project untitled (kit: gcc48)
When executing step 'Make'
12:30:20: Elapsed time: 00:01.
and
RAYMONDs-MacBook-Air:~ raymondvaldes$ /Applications/Xcode.app/Contents/Developer/usr/bin/g++ --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix
Finally, here is my simple working example:
#include <iostream>
#include <complex>
#include <cmath>
#include <random>
int main()
{
std::cout << "Hello World!" << std::endl;
return 0;
}
and my pro file.
cache()
TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt
QMAKE_CXXFLAGS += -std=c++11
SOURCES += main.cpp
Thank you.

Answer 1

I finally solved this issue and I am now able to use my MacPorts GCC48 compiler in QT Creator. As I suspected I needed to create a gcc48 mkspecs folder in the QT Directory and feed the folder name to the QT Creator custom compiler setup screen. I created "macs-g++48" folder that was copied from the generic "macs-g++" folder in "~path~QT/5.1.x/clang_64/mkspecs". I had to modify qmake.conf. I commented out
#include(../common/g++-macx.conf)
#include(g++-base.conf)
and placed their contents within quake.conf while making the following modifications:
QMAKE_CC = gcc-mp-4.8
QMAKE_CXX = g++-mp-4.8