move setting variables and run-as-stack-user code

Change the over all flow so that the default settings are
filled in in the outside shell (not inside the '()' and 'tee').

This way, those variables pass through to the subshell, but they're
also available in the parent shell at the end for outputting status.

Also, exit failure rather than success if 'exec' to run as stack
user failed.
1 file changed