elpa-restart-emacs software package provides restart emacs from within emacs, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install elpa-restart-emacs
elpa-restart-emacs is installed in your system.
Make ensure the elpa-restart-emacs package were installed using the commands given below,
$ sudo dpkg-query -l | grep elpa-restart-emacs *
You will get with elpa-restart-emacs package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Lisp |
| Package | elpa-restart-emacs |
| Version | 0.1.1-1 |
| Description | restart emacs from within emacs |
| Sub Section | Lisp |