Apt Updates Scripts – What is Apt-Fast and Should It Be Used

The package list, as it names indicates, is the list of all packages contained in all the repositories in your sources.list configuration files. Most of the package managers (including APT) uses packages list.

This lists reside in the /var/lib/apt/lists/ directory and apt systems update them whenever you update the lists (please, note that there is a difference between update and upgrade) apt will fetch the lists from the repositories and store it locally for future uses. Whereas you run any command in apt this list are loaded an processed and your commands (like install, remove, upgrade).

Reference:

• https://www.debian.org/doc/manuals/debian-reference/ch02.en.html

First off, an important clarification:

The terms "Stable Release Updates" and "Security Updates" (don't forget them!) apply to packages in main, universe, restricted and multiverse. PPAs or other third-party repositories may have their own release schedules and policies. In your screenshot I see "google-chrome-stable" -- this is not a Ubuntu package and it does not follow the Ubuntu release schedule.

Having said that, here's what you asked for:

• For every Ubuntu update, the point of reference is the Launchpad bug. This is where you can find most of the information related to the problem(s) and solution(s).

  You can get the bug numbers by checking the changelog of each package. For example, as of writing, this is the last entry from apt-get changelog nautilus:

  nautilus (1:3.14.2-0ubuntu9.1) vivid; urgency=low
  
    * debian/patches/ignore-no-desktop-if-not-first-launch.patch:
      - Don't shut off the desktop when external application calls nautilus
        --no-desktop on a running GNOME desktop. (LP: #1453655)
  
   -- Chow Loong Jin <hyperair@debian.org>  Wed, 24 Jun 2015 11:50:03 +0800
  

  As you can see, the log entry refers to bug #1453655.

  For security bugs, generally the bug report is private (to prevent malicious people from accessing critical information) and, generally, instead of the Launchpad bug number you'll find the CVE number.

• Patches applied by Ubuntu (or by Debian) are in the source package, in the debian/patches directory. If you want to download the source packages for Nautilus, use apt-get source nautilus.

  If a Stable Release Update or a Security Update introduces a new version of the software (e.g. a new version of Firefox), you'll have to look upstream for the full delta.

  Not all package sources are available under version control (git, hg, bzr, ...).

• Discussion generally happen on Launchpad. If necessary, the ubuntu-devel mailing list may be used too.

• People responsible for updates are the people who provide the updates (package maintainers or contributors), the Ubuntu SRU Team and the Ubuntu Security Team.

  Note that not all of these people are Canonical employees. Be kind and don't forget those contributors who use their spare time to maintain stability and security in Ubuntu :-)

• The process for Stable Release Updates and Security Updates is documented on the Ubuntu Wiki: https://wiki.ubuntu.com/StableReleaseUpdates and https://wiki.ubuntu.com/SecurityTeam/UpdateProcedures