elpa-editorconfig software package provides coding style indenter for all editors - Emacsen plugin, 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-editorconfig
elpa-editorconfig is installed in your system.
Make ensure the elpa-editorconfig package were installed using the commands given below,
$ sudo dpkg-query -l | grep elpa-editorconfig *
You will get with elpa-editorconfig package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Editors |
| Package | elpa-editorconfig |
| Version | 0.4+git20151028.3835e4-1 |
| Description | coding style indenter for all editors - Emacsen plugin |
| Sub Section | Editors |