Install a debian package from Testing

2026-07-16

My debian experiments progressing, i noticed an issue: my kanshi config didn't work.

Turns out, in 2026, the latest debian ships a kanshi version from 2023, which is missing a feature i need.

So we:

add the testing repo

in /etc/apt/sources.list, add deb http://deb.debian.org/debian testing main contrib non-free

avoid updating literally every package to testing

in /etc/apt/preferences.d/99-testing-pin we add

Package: *
Pin: release a=testing
Pin-Priority: -1

install to try it out

apt update
apt install -t testing kanshi

make it permanent so apt won't downgrade (due to the minus priority)

edit preferences.d/99-testing-pin:

Package: *
Pin: release a=testing
Pin-Priority: -1

Package: kanshi
Pin: release a=testing
Pin-Priority: 1001