This should work, although I haven't tested it yet.
In the future it may be easier to simply download the other install
scripts from this install script. That way we solve the problem of
having to unzip this entire repository in the installation image.
This should ensure that a user knows what they're doing before running
the install scripts. Note that parted will also ask for a confirmation
before overwriting existing data.
This not only fixes the issue where set -x would cause the read
line to be altered, but also separates user input from what the
install scripts actually do.