To use this repository, you need to add this to your sources.list: deb https://people.debian.org/~sthibault/tmp/stretch-tmp ./ and run sudo apt-key adv --recv-keys --keyserver keyring.debian.org 900CB024B67931D40F82304BD0178C767D069EE6 sudo apt update and then you can install packages like this: sudo apt install somepackage/stretch-tmp-sthibault