Problems using clamp with explicit subcommand class

explicit_subcommand_class.rb

#! /usr/bin/env ruby

require 'clamp'

class InitCommand < Clamp::Command

  def execute
    puts "initializing from another file"
  end

end

class MainCommand < Clamp::Command

  option '--debug', :flag, "Show stacktraces on error", :default => false

  subcommand "init1", "Initialize the repository (from another file)", InitCommand

  subcommand "init2", "Initialize the repository (inline)" do
    def execute
      puts "initializing inline"
    end
  end

end


MainCommand.run

gistfile1.txt

$  ./explicit_subcommand_class.rb --help
Usage:
    explicit_subcommand_class.rb [OPTIONS] SUBCOMMAND [ARGS] ...

Parameters:
    SUBCOMMAND                    subcommand name
    [ARGS] ...                    subcommand arguments

Subcommands:
    init1                         Initialize the repository (from another file)
    init2                         Initialize the repository (inline)

Options:
    --debug                       Show stacktraces on error (default: false)
    --debug                       Show stacktraces on error (default: false)
    --help                        print help


$ ./explicit_subcommand_class.rb init1 --help
Usage:
    explicit_subcommand_class.rb init1


$ ./explicit_subcommand_class.rb init2 --help
Usage:
    explicit_subcommand_class.rb init2 [OPTIONS]

Options:
    --debug                       Show stacktraces on error (default: false)
    --help                        print help