The one-character Options flag does not seem to work anymore

[AliSoftware]

Given an option defined like this:

let outputOption = Option("output", OutputDestination.Console, flag: "o", description: "The path to the file to generate (Omit to generate to stdout)")

Using -o doesn't work, while using --output does.
(The -o doesn't show up in the help either btw, not sure that's expected)

$ swiftgen images -o out.swift share/swiftgen/fixtures/Images.xcassets
Unknown Arguments: -o

Options:
    --output - The path to the file to generate (Omit to generate to stdout)
    --template - The name of the template to use for code generation (without the "images" prefix nor extension).
    --templatePath - The path of the template to use for code generation. Overrides -t.
    --enumName - The name of the enum to generate

$ swiftgen images --output out.swift share/swiftgen/fixtures/Images.xcassets
File written: out.swift

Was working in Commander 0.2.2, stopped working on 3.0.0