My understanding is that Ubuntu is based on Debian. For example, on the Wikipedia page for Ubuntu it states "It is a Linux distribution based on the Debian architecture." How can I find out what version of Debian a particular version of Ubuntu is based on (if any)?
For example, the current stable release of Ubuntu is "Artful Aardvark" (17.10) which announces that it is based on the Linux 4.13 kernel, but does not seem to say anything about the Debian version.
The current stable release of Debian is code named "Stretch" (9.2) which advertises a 4.9 kernel (on the afore-linked Stretch page). How can I find out the details of the relationship between them? Is there a particular command that will reveal this information?
Best Answer
Ubuntu releases aren’t based on Debian releases. During the development of an Ubuntu release, packages are imported from Debian unstable, until the Debian import freeze (in the past, LTS releases imported from testing, and this is what the linked wiki page still suggests; however looking at my packages shows that 18.04 is importing packages from unstable). This means that a given Ubuntu release will have non-Ubuntu-maintained packages in whatever version was in Debian at the time of the import freeze (barring explicit sync requests); but that doesn’t match what the next release of Debian will contain.
So trying to tie a release of Ubuntu to a release of Debian would just end up being misleading.
You can look at the contents of
/etc/debian_versionto see the Debian codename of the version (under construction) from which packages were pulled; you can also match Debian import freeze dates from the release schedules (for example, Artful’s, Bionic’s, Cosmic’s, or Disco’s). You’ll see from this that the same Debian release feeds multiple Ubuntu releases (e.g. Stretch, which ended up being Debian 9, fed Xenial, Yakkety, Zesty and Artful; Buster, which will end up being Debian 10, fed Bionic and Cosmic, and is feeding Disco), with quite different package versions each time.