How can the existing environment variable FOOBAR be suppressed for the execution of the script./myscript only?

The `unset -v FOOBAR` command unsets the variable in the current shell's environment, making the change persistent for the current shell session, which is not limited to the script's execution.

The `set -a` command marks variables for automatic export, and `FOOBAR=""` sets the variable to an empty string, but it does not suppress or remove it from the environment for the script's execution.

The `env -u FOOBAR` command removes the variable `FOOBAR` from the environment passed to the subsequent command `./myscript`, ensuring the script runs without that variable while the `FOOBAR` variable in the parent shell remains untouched.

The `env -i` command starts the command with an *empty* environment, meaning all existing variables are suppressed, which is more restrictive than just suppressing `FOOBAR`.