How to fail a form

PowerShell Universal
1 
Product: PowerShell Universal
Version: 2.4.0 Sept 24 Nightly
System Powershell 5.1 Environment

How can I intentionally fail a script attached to a form (in a page) so that it shows an informative error to the user in the failure text? Ex: Failed: Invalid computer name or somesuch.

2

The nightly build should actually do this now. If you throw an error and set the error action to stop for the script, the thrown error will be displayed.