ajalt/clikt 3.1.0 on GitHub

Added required() and defaultLazy() for nullable flag options like switch().
Added support for generating autocomplete scripts for Fish shells (thanks to @faogustavo for the initial PR)
Added CompletionCommand and CliktCommand.completionOption() that will print an autocomplete script when invoked, as an alternative to using environment variables.

Updated Kotlin to 1.4.21
@argfiles now allow line breaks in quoted values, which are included in the value verbatim. You can now end lines with \ to concatenate them with the following line.