The Package Archive

Note

This content comes from the wiki It has not yet been reviewed for currency or accuracy.

All current official Ubuntu packages are stored in the master archive, which is widely mirrored. A search interface is available at http://packages.ubuntu.com. Old versions can be retrieved from Launchpad.

It is administered by the archive administration team.

Uploading

If you are not yet an official Ubuntu developer, you can arrange for your package to be uploaded via the Sponsorship process.

Packages are uploaded via FTP using dput or dupload.

Notes for preparing your upload:

  • Make source-only uploads, i.e. use “dpkg-buildpackage -S”

  • If you need to include the orig tarball as well, use parameters -S -sa

When your upload is processed (typically within a matter of minutes), you will receive an email with the result of your upload, whether it succeeds or fails, unless you use an unregistered email address. The system will only send mail to an address which belongs to a launchpad account which is a member of the relevant team for uploading. E.g. motu for universe and ubuntu-core-dev for main.

Your upload must be signed by a GPG key registered in Launchpad. If the signature cannot be traced to a member of the appropriate team, then the upload will be silently rejected.

To add a new package to Ubuntu, simply upload it as usual. Any new packages uploaded are put in a queue to be checked by the administrators before being included.

Ubuntu Development/Uploading has much more information about the topic.

Autobuilding and publishing

Once an upload has been accepted, it takes some time to be built and published in the archive. For simple packages, this is usually on the order of an hour, but varies depending on release activity (uploads may be temporarily suspended), the time needed to build the package (including other packages in the build queue), and other factors.

After a package has been built, the next publisher run that starts at 3 and 33 minutes past each hour will process it, usually finishing towards the end of that half-hour; at the end of that process it will be visible in the public archive.

Notification of changes

Notifications of uploads are sent to a mailing list. A different list is used for each Ubuntu release:

Question

Do we, in principle, want to keep this list? If so, we should consider trying to create it in a way that makes it better maintainable (otherwise it will get this out of date again).

You can find changelogs for all packages at http://changelogs.ubuntu.com/changelogs/ (this is the source used by update-manager and Synaptic).

Syncing and merging

(See the Release Process / Merge Process rationale

Most packages in Ubuntu originate elsewhere, including Debian and related package repositories.

A sync copies a source package verbatim from an external repository into Ubuntu, overwriting any package of the same name. This is used when a newer version of it is available, and should be included in Ubuntu, and happens automatically during some phases of the release cycle. To request a sync, follow the Sync Request Process.

A merge is a three-way merge of a package which originated in an external repository. This is used when there is a newer version available from the external repository, but the package has also been modified (branched) in Ubuntu. Merge-o-Matic assists with this work, and the Merging page explains how and when to merge. Packages which are maintained in Bazaar can and should be merged using Bazaar itself.

The “Last Uploader” column in the Merge-o-Matic output is the default assignee for the merge, following the “touched-it-last” maintenance principle. However, you can and often should grab other people’s merges if they don’t have time or you feel you can do a better job. It’s polite and often a good idea (though not mandatory) to contact the other person first to make sure you aren’t duplicating work.

Backports work similarly to syncs, but have somewhat different requirements. To request a backport, follow the Ubuntu Backports process.

Consistency

The archive is periodically checked for various inconsistencies, such as incorrect dependency relationships between packages.

  • Packages that are uninstallable – due to dependencies that cannot be satisfied.

  • Ubuntu Development/NBS - binary packages that are no longer built by any source package. These packages are not automatically removed from the archive, since generally they still have reverse dependencies (packages depending on them).

Freezes

Freezes are restrictions on which changes can be uploaded in order to try and stabilize Ubuntu for release. There are various different freezes that happen at different times in the cycle, and they are of different types, affect different packages, and have different procedures for uploading during them, so understanding them all can be difficult.

You can see which freezes happen and when on the Release Schedule, and each is linked to a page about that particular freeze, so that is a great place to go for the information. This page will provide a bit more explanation about the types of freezes and how to handle them.

Freezes are generally also announced on ubuntu-devel-announce, so subscribing to that can keep you up-to-date. However, there aren’t reminders about upcoming freezes posted to that list, so keep on top of which freezes are upcoming will help you to meet the deadlines in your work.

Uploading restrictions

There are two ways that freezes are enforced, which are known as “soft” and “hard” freezes. Knowing whether a particular freeze is soft or hard is important, as it will allow you to know what effect uploading will have, and who needs to be aware of changes that you make for them to be included.

Soft freezes

Soft freezes have no mechanism in the archive software to enforce them, they just rely on each developer to ensure that they only upload appropriate changes.

For instance, Feature Freeze is a soft freeze, as you can still upload as before, you are just required to seek exceptions for new features.

Most importantly, freezes for the alpha releases of Ubuntu are soft freezes. This means that nothing will prevent your changes from entering the archive, so you must ensure that they don’t interfere with the process of releasing the alpha. Convention for milestone stabilization is to upload to -proposed, during this freeze interval. See the section on milestone freezes later for more information on what this means.

Hard freezes

In contrast to soft freezes, hard freezes flick a switch in the archive software such that all uploads are not immediately accepted, they instead end up in the UNAPPROVED Queue. Packages remain in this queue until they are explicitly accepted by an Archive Administrator.

This means that your changes can be reviewed before they are accepted, so that extra review can be done, and it is not left to your discretion to enforce the rules of the freeze.

While this could mean that you could upload with less care, it is not wise to, as those who can review are generally very busy at this time already, and extra work at these crucial periods is not appreciated. It is generally a good idea to ensure that someone on the release team knows that you will be making an upload to fix the particular issue before you do so (fixing a release critical bug is generally permission enough).

Managing components

Ubuntu packages are classified into components according to maintenance and licensing criteria, a process which is described in Seed management.

Packages sometimes move from one component to another, according to policy or licensing changes, as managed by the archive administrators. Special consideration is necessary when packages move into main or restricted, as this implies a commitment of ongoing maintenance. Such changes must follow the Main Inclusion Process.

Autobuilders

Ubuntu source packages are automatically built for a variety of platforms by Launchpad, which provides build status information. Build log files are available from Launchpad as well, by searching for the package and selecting a version.

Some supplementary information about the build infrastructure is available on Build Daemons.

Removing Packages

Packages which are removed from Debian are semi-automatically removed from Ubuntu universe on a regular basis by the administrators. However, packages are not removed from Ubuntu Main without explicit request, nor are packages which originated elsewhere. To request removal of such a package, file a bug against the package.

The bug must have the following elements:

  • Which release to remove it from (e.g., hardy)

  • Whether to remove both the source package and all binary packages

  • A rationale for why they should be removed

  • Confirmation that the binary packages have no rdepends (no other package depends on them)

    • There is checkrdepends in ubuntu-archive-tools, but it needs a mirror to work with.

    • There is reverse-depends and reverse-depends -b (build depends) in ubuntu-dev-tools, but it can return false positives for alternative dependencies.

If you are not an Ubuntu Developer use the following Sponsorship process. If you are an Ubuntu Developer, then subscribe the ubuntu-archive team to the bugs. If you need help deciding whether a package ought to be removed, please discuss on the ubuntu-devel mailing list rather than asking the archive administrators.

Refer to https://launchpad.net/ubuntu/+source/<source package> for the reason of the removal of a specific package.

Architectures

Packages are typically built for each of several architectures. For example, the hello package is built on i386, amd64, etc. These are divided into categories according to their level of use and official support by the project.

Official architectures

These are officially supported and maintained by the Ubuntu project. Canonical provides server resources to build, store and distribute packages and installation media for them, and the core development team is responsible for their upkeep.

Build failures on these architectures are considered serious bugs. Each official Ubuntu release and update includes appropriate support for these architectures. There may or may not be a team which is specifically responsible for architecture-specific issues. The kernel team builds and tests the Ubuntu kernel on these architectures:

  • amd64

  • armhf

  • i386

Unofficial architectures

These are maintained on a best-effort basis by interested volunteers in the Ubuntu community. Each architecture has a corresponding community team formed of the developers who support it. Canonical provides server resources to build, store and distribute packages and installation media for ports, however, the porting teams are responsible for their operation and maintenance, including the kernel, toolchain and build infrastructure.

Build failures are not considered a serious issue by the core team. Ports may issue new releases or updates out of sync with official Ubuntu releases.

Primary architectures

These are provided on archive.ubuntu.com, and are widely mirrored.

  • amd64

  • i386

Ports

These are provided only on ports.ubuntu.com, and are not generally available on the mirror network. This decision is made on the basis of levels of use; mirrors on the mirror network only have so much space available, and so we only designate as primary those architectures which have very high download rates.

The ports system was announced here

Summary as of Ubuntu 14.04

Official

Unofficial

Primary

amd64, i386

Ports

armhf

arm64, powerpc, ppc64el

Installation media

Installation media (for CDs, DVDs, USB drives, etc.) are built from the package archive, and published on different hosts as follows.

releases.ubuntu.com

releases.ubuntu.com hosts the most frequently downloaded images. It is widely mirrored. All images here are officially supported by the Ubuntu project.

cdimage.ubuntu.com

cdimage.ubuntu.com hosts less frequently downloaded images. It is not widely mirrored due to its very large size. Some images here are officially supported by the Ubuntu project and some are not; if an image is on cdimage.ubuntu.com, it simply means that it won’t fit on releases.ubuntu.com. For example, Ubuntu DVD images are hosted on cdimage.ubuntu.com.