elpa-buttercup software package provides behaviour-driven testing for Emacs Lisp packages, 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-buttercup
elpa-buttercup is installed in your system.
Make ensure the elpa-buttercup package were installed using the commands given below,
$ sudo dpkg-query -l | grep elpa-buttercup *
You will get with elpa-buttercup package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Lisp |
| Package | elpa-buttercup |
| Version | 1.5-2 |
| Description | behaviour-driven testing for Emacs Lisp packages |
| Sub Section | Lisp |