> We should add an explicit feature for this

If we need to write a wrapper program for that, I would say that no, we don't "have to" provide something in the stdlib.

In OpenStack, I wrote prlimit.py which is a preexec-like wrapper program to apply resource limits when calling a program. It's just a pure Python implementation of the Unix prlimit program. The Python implementation is used when the prlimit progrma is not available.

https://github.com/openstack/oslo.concurrency/blob/master/oslo_concurrency/prlimit.py

IMHO it's perfectly fine to explain that a wrapper program is needed to implement preexec-like features.