With the new picocli 3.0 programmatic API it should be possible to create a groovy DSL that is (or almost is) a drop-in for CliBuilder, with additional benefits:

• support for subcommands
• support for strongly typed positional parameters
• support for mixins for reuse
• automatic help (remove boilerplate)
• ANSI colors in usage help
• groovy application command line autocompletion