also i think this tutorial is good, but it misses some things like you need to have msys-zlib-bin and msys-gcc compiler to able to make libpng and libqrencode.
The tutorial states you have to use a mingw-builds toolchain:
Make sure no mingw packages are checked for installation or present from a previous install. Only the above msys packages should be installed. Also make sure that msys-gcc and msys-w32api packages are not installed.