generate_bundler_executable_stubs

# File lib/bundler/installer.rb, line 99
    def generate_bundler_executable_stubs(spec, options = {})
      if options[:binstubs_cmd] && spec.executables.empty?
        options = {}
        spec.runtime_dependencies.each do |dep|
          bins = @definition.specs[dep].first.executables
          options[dep.name] = bins unless bins.empty?
        end
        if options.any?
          Bundler.ui.warn "#{spec.name} has no executables, but you may want "              "one from a gem it depends on."
          options.each {|name, bins| Bundler.ui.warn "  #{name} has: #{bins.join(", ")}" }
        else
          Bundler.ui.warn "There are no executables for the gem #{spec.name}."
        end
        return
      end

      # double-assignment to avoid warnings about variables that will be used by ERB
      bin_path = Bundler.bin_path
      bin_path = bin_path
      relative_gemfile_path = Bundler.default_gemfile.relative_path_from(bin_path)
      relative_gemfile_path = relative_gemfile_path
      ruby_command = Thor::Util.ruby_command
      ruby_command = ruby_command
      template_path = File.expand_path("../templates/Executable", __FILE__)
      if spec.name == "bundler"
        template_path += ".bundler"
        spec.executables = %(bundle)
      end
      template = File.read(template_path)

      exists = []
      spec.executables.each do |executable|
        binstub_path = "#{bin_path}/#{executable}"
        if File.exist?(binstub_path) && !options[:force]
          exists << executable
          next
        end

        File.open(binstub_path, "w", 0o777 & ~File.umask) do |f|
          if RUBY_VERSION >= "2.6"
            f.puts ERB.new(template, :trim_mode => "-").result(binding)
          else
            f.puts ERB.new(template, nil, "-").result(binding)
          end
        end
      end

      if options[:binstubs_cmd] && exists.any?
        case exists.size
        when 1
          Bundler.ui.warn "Skipped #{exists[0]} since it already exists."
        when 2
          Bundler.ui.warn "Skipped #{exists.join(" and ")} since they already exist."
        else
          items = exists[0...-1].empty? ? nil : exists[0...-1].join(", ")
          skipped = [items, exists[-1]].compact.join(" and ")
          Bundler.ui.warn "Skipped #{skipped} since they already exist."
        end
        Bundler.ui.warn "If you want to overwrite skipped stubs, use --force."
      end
    end