# File lib/capistrano/configuration/actions/invocation.rb, line 264
        def add_default_command_options(options)
          defaults = self[:default_run_options]
          options = defaults.merge(options)

          env = self[:default_environment]
          env = env.merge(options[:env]) if options[:env]
          options[:env] = env unless env.empty?

          shell = options[:shell] || self[:default_shell]
          options[:shell] = shell unless shell.nil?

          options
        end