ruby/rubygems · error · Gem::CommandLineError

Please specify an executable to run (e.g. #{program_name} CO

Error message

Please specify an executable to run (e.g. #{program_name} COMMAND)

What it means

Error "Please specify an executable to run (e.g. #{program_name} COMMAND)" thrown in ruby/rubygems.

Source

Thrown at lib/rubygems/commands/exec_command.rb:116

      if options[:version].none?
        options[:version] = Gem::Requirement.new(gem_version)
      else
        options[:version].concat [gem_version]
      end
    end

    if options[:prerelease] && !options[:version].prerelease?
      if options[:version].none?
        options[:version] = Gem::Requirement.default_prerelease
      else
        options[:version].concat [Gem::Requirement.default_prerelease]
      end
    end
  end

  def check_executable
    if options[:executable].nil?
      raise Gem::CommandLineError,
        "Please specify an executable to run (e.g. #{program_name} COMMAND)"
    end
  end

  def print_command
    verbose "running #{program_name} with:\n"
    opts = options.reject {|_, v| v.nil? || Array(v).empty? }
    max_length = opts.map {|k, _| k.size }.max
    opts.each do |k, v|
      next if v.nil?
      verbose "\t#{k.to_s.rjust(max_length)}: #{v}"
    end
    verbose ""
  end

  def install_if_needed
    activate!
  rescue Gem::MissingSpecError

View on GitHub (pinned to 86cbb817a3)

When it happens

Trigger: Thrown at lib/rubygems/commands/exec_command.rb:116 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/38383b6e70511922. Report an issue: GitHub.