Unfortunately guestfish may error out silently (no return code
of 1), making hunting down the error a bit obscure. To combat
this we add a bunch of stdout output to the script, and look
for that final step to validate success. To make this work, we
need to copy the script over and execute it with the command
module, because the script module puts everything into stderr.
Change-Id: I8e514ceb2462870721745c9445ec149864a45f4d
4e9c1c5fd8