add per-shell test for shell termination

^{Originally posted by **johhnry** March 17, 2022}
Hi,

We have a render farm setup where we launch renders in a Rez environment like: `rez env houdini -- hrender ...`

The issue we are facing is that when trying to kill a running task on a computer, the visible PID is Rez's one and not `hrender`'s one for example.

I would have thought that killing Rez was killing the subprocess that was spawned but this is not the case and it stills run in the background. This is quite problematic since we launch renders on machines that are not only dedicated to the render farm and users must be able to kill jobs.

My question is: is there a reliable way to kill the child process in a Rez resolved environment?

I noticed that there is the `rez env --new-session` argument but I don't quite understand how it works on Windows and how it might solve our issue (I tried `rez env --new-session maya -- maya` and closed the terminal but nothing happened)

Thanks!