# File lib/bundler/cli.rb, line 167
    def exec(*)
      ARGV.delete("exec")

      # Set PATH
      paths = (ENV["PATH"] || "").split(File::PATH_SEPARATOR)
      paths.unshift "#{Bundler.bundle_path}/bin"
      ENV["PATH"] = paths.uniq.join(File::PATH_SEPARATOR)

      # Set BUNDLE_GEMFILE
      ENV["BUNDLE_GEMFILE"] = Bundler::SharedHelpers.default_gemfile.to_s

      # Set RUBYOPT
      rubyopt = [ENV["RUBYOPT"]].compact
      if rubyopt.empty? || rubyopt.first !~ /-rbundler\/setup/
        rubyopt.unshift "-rbundler/setup"
        rubyopt.unshift "-I#{File.expand_path('../..', __FILE__)}"
        ENV["RUBYOPT"] = rubyopt.join(' ')
      end

      begin
        # Run
        Kernel.exec *ARGV
      rescue Errno::EACCES
        Bundler.ui.error "bundler: not executable: #{ARGV.first}"
      rescue Errno::ENOENT
        Bundler.ui.error "bundler: command not found: #{ARGV.first}"
        Bundler.ui.warn  "Install missing gem binaries with `bundle install`"
      end
    end