qbs.profile does not function as expected

Hello,

while playing around with profiles to implement a conan toolchain file generator I stumbled across two odd behaviors using profiles:
1.) set `qbs.profile(s)` on project level (the top project level) does not affect any products
2.) profiles in references qbs files are not recognized

I added an example project. Compiling with `qbs build -f qbs_profile_bug.qbs` will lead to the stated errors.