STAN on multiple cores occasionally crashing Linux without overwhelming memory

I wonder if we are doing something dumb in Stan when the user has a ton of non/infinite values? @rok_cesnovar @mathesong it may be helpful to run this with valgrind and heaptrack like

valgrind --leak-check=full --show-leak-kinds=all  ./cmdstanr_test sample data file=cmdstanr_test_data- output file=output_1.csv

heaptrack ./cmdstanr_test sample data file=cmdstanr_test_data- output file=output_1.csv

to see if we have leaks or bad memory reads/writes somewhere. I’m really not sure what would cause a full freeze without also taking up all the users memory. I think we’d have to be writing memory to somewhere that leads to an unrecoverable state for the OS