Yes! I finally managed to install rstan and the example finished running too! It still gives this warning before starting to sample:
ld: warning: text-based stub file
/System/Library/Frameworks//CoreFoundation.framework/CoreFoundation.tbd and library file /System/Library/Frameworks//CoreFoundation.framework/CoreFoundation are out of sync. Falling back to library file for linking.
Doest that matter?