Ubuntu Linux has shipped /etc/debian_version that is carried over from upstream Debian and in turn just indicating the Debian Sid development version from which the packages are arrived. Besides it being inaccurate, /etc/os-release has been the long preferred standard for reading the OS release information. Thus finally Ubuntu developers are looking at dropping the /etc/debian_version file.

Ubuntu dropping /etc/debian_version would be a long time coming. Going all the way back to 2005 was this bug report raising the issue of /etc/debian_version being inaccurate on Ubuntu and potentially confusing user-space tooling relying on that file. Yet over the past 20+ years it has remained with the recommendation tools just rely instead on lsb_release or /etc/os-release.

Finally now Ubuntu developer Benjamin Drung is looking to take action on removing /etc/debian_version moving forward. Hopefully this historical artifact will finally be removed in 2026 with Ubuntu 26.10.