ruby/rubygems · error · Gem::UnknownCommandError

Unknown command #{unknown_command}

Error message

Unknown command #{unknown_command}

What it means

Error "Unknown command #{unknown_command}" thrown in ruby/rubygems.

Source

Thrown at lib/rubygems/command_manager.rb:206

      end
    when /^-/ then
      alert_error clean_text("Invalid option: #{args.first}. See 'gem --help'.")
      terminate_interaction 1
    else
      invoke_command(args, build_args)
    end
  end

  def find_command(cmd_name)
    cmd_name = find_alias_command cmd_name

    possibilities = find_command_possibilities cmd_name

    if possibilities.size > 1
      raise Gem::CommandLineError,
            "Ambiguous command #{cmd_name} matches [#{possibilities.join(", ")}]"
    elsif possibilities.empty?
      raise Gem::UnknownCommandError.new(cmd_name)
    end

    self[possibilities.first]
  end

  def find_alias_command(cmd_name)
    alias_name = ALIAS_COMMANDS[cmd_name]
    alias_name ? alias_name : cmd_name
  end

  def find_command_possibilities(cmd_name)
    len = cmd_name.length

    found = command_names.select {|name| cmd_name == name[0, len] }

    exact = found.find {|name| name == cmd_name }

    exact ? [exact] : found

View on GitHub (pinned to 86cbb817a3)

When it happens

Trigger: Thrown at lib/rubygems/command_manager.rb:206 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ruby/rubygems@86cbb817a3 (2026-08-23). Data as JSON: /api/errors/4ba137b52ec55a60. Report an issue: GitHub.