Print statements inside a model are buffered into a stringstream and only printed when log_prob returns #3233

Summary:

In situations like stan-dev/cmdstan#1207, where there is an infinite loop which never exits, a user may try to debug-by-print the loop condition. This will never be useful, as the infinite loop prevents the code from exiting and actually logging to the user.

Relevant code:

Current Version:

v2.33.0