extra-cmake-modules software package provides Extra modules and scripts for CMake, 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 extra-cmake-modules
extra-cmake-modules is installed in your system.
Make ensure the extra-cmake-modules package were installed using the commands given below,
$ sudo dpkg-query -l | grep extra-cmake-modules *
You will get with extra-cmake-modules package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Libraries |
| Package | extra-cmake-modules |
| Version | 5.27.0-1 |
| Description | Extra modules and scripts for CMake |
| Sub Section | Libs |