Note that vm/many doesn't work (as you saw) due to file descriptors
(lack of a real destroy and cleanup).

These tests don't always work.
10.1 may or may not.
20.3 doesn't, so it's commented out in Script

Get errors, after creating some VMs, like:

Cannot create virtual machine on pc19.cs.ucdavis.edu ... exiting!

or more verbose, starting with

jrvm exception: unable to create new native thread
java.lang.OutOfMemoryError: unable to create new native thread
