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Importing changes from Debian (merges & syncs)

This article explains how and why changes from Debian are imported into Ubuntu.

How does Ubuntu import changes from Debian?

Because Ubuntu is derived from Debian and uses the same package management system (APT), most changes made to Debian can also be applied to Ubuntu.

Syncs and merges are the two processes through which Ubuntu developers integrate updates and improvements from Debian into the Ubuntu package archive.

Sync

Beginning with the archive opening for a new Ubuntu release until the Debian Import Freeze, new packages and packages with higher version identifiers than the corresponding Ubuntu packages are automatically copied from Debian unstable (also known as Code name “Sid”) into the Ubuntu package archive if the corresponding Ubuntu packages do not carry Ubuntu Delta. This process is called “synchronisation with Debian”, or “sync” for short.

On request (via a Launchpad bug-ticket), Archive Admins can sync a package from Debian even if the Ubuntu package carries Ubuntu Delta. In this case, the Ubuntu Delta will be dropped. A good example is when Ubuntu-specific changes have been merged into the Debian package or Upstream project and are no longer needed.

Note

The Feature Freeze (FF) is often scheduled for the same day as the Debian Import Freeze.

After the Debian Import Freeze and before the Final Release, you must also request the respective freeze exception.

After the Final Release, you must follow the Stable Release Updates (SRU) process. For additional details about the freezes, see the Ubuntu development process article.

Merges

When importing a newer Debian package into Ubuntu, a merge must be performed if the corresponding Ubuntu package carries Ubuntu Delta that needs to be partially or fully applied to the Debian package.

The Ubuntu Merge-o-Matic (MoM) automatically performs merges and publishes the reports on this page. See the lists of outstanding merges for:

• main

• universe

• restricted

• multiverse

To complete a merge, interaction and supervision by Ubuntu maintainers are required. See the tutorial and how-to for details on performing a merge.

See the section Components in the article that explains the Ubuntu package archive for an explanation of main, universe, restricted and multiverse.

Why does Ubuntu import changes from Debian?

Ubuntu incorporates changes from Debian through merging and syncing to leverage the extensive work and improvements made by the Debian community. Debian provides a stable foundation and a vast repository of packages. By integrating changes from Debian, Ubuntu can focus on refining the user experience. At the same time, the consistency between Ubuntu and Debian allows for sharing resources (e.g., testing and bug fixing) and contributing back to the open-source ecosystem, ultimately benefiting both distributions and their users.