I have managed to (somehow) cross-compile Qt5 with the Mingw-w64 Project\'s compiler for 32-bit Windows. All of the libraries have been installed to ~/i686-w64-mingw32
Finding the location of the wrong library:
My personal solution:
In my experience, MS Windows' way of choosing the location within the %PATH% can be very erratic. Last time, I added one source file with a single function and included that function into my code. The program would always pick the wrong libstdc++-6.dll even when I deleted all the function's code and left only the 'return' statement. Every time that function was commented out (excluded), the program would run normally again. I suspect that sometimes Windows chooses PATH from "System Variables" and avoids "User variables" PATH (your Windows account's PATH) for some reason.