If you look at the last posting, you'll see the template is very verbose and optimized for the build tool. Changed it to be more like the actual usage mentioned on the man page: so, exit's manpage says:
And our exit template now says:
usage => "?returnCode:int=0?",
Which automatically generates code to treat it as an optional argument, generates the appropriate usage message if the user miscalls, expects the argument to be an integer (and carps properly if it's not), and sets the default value to 0.