mirror of
https://git.launchpad.net/~ubuntu-release/britney/+git/britney2-ubuntu
synced 2025-04-19 15:11:09 +00:00
3ddac110c6
In 'partial source' mode, which we use in Ubuntu, we merge the target
(release pocket) with the source (proposed), so that proposed-migration
has a view of the complete state of the archive when it is migrating.
This merging must not be done when a package has been built in the
source suite. If it is done incorrectly, proposed-migration will see the
previous binary packages as existing when they should not.
We have code to handle this already, but it's wrong in the case of
arch:all binaries. This comes up in two ways
- If a source package builds *only* arch:all binaries, it is not
expected that builds will be created on arches other than the one
which builds arch:all packages (amd64 currently). If that is built
then the package is complete, we shouldn't merge any old binaries
such as dropped arch:all ones from the target.
- Relatedly, if other non-arch-all packages exist, an arch:all package
isn't an indication that a build has taken place on other arches
than the all buildd arch.
Fixing both of these stops old binaries being merged into a new source
when it's been built and arch:all packages are involved.
Britney - Keeps suites installable and up to date
Britney is a program to compute an update of a Debian-based package suite by feeding it updates from (one or more) source-suite(s). A few known use cases:
- Debian uses it to update testing based on unstable
- Ubuntu uses it to update their latest development suite using a "hidden" -proposed-updates suite as source
Britney's primary goal is too keep packages in the target suite installable (e.g. Debian testing) while keeping it up to date with its primary source suite (e.g. Debian unstable).
Installing, configuring and using Britney
Please see [doc/setting-up-britney.rst].
Migration items
Britney generally works with a "migration item", which is a group of binary packages (and possibly a source package). Packages are bundled into these migration items under the following rules:
- "source migration": An update of the source package. This will include all the binary packages built from that source version (regardless of architecture).
- Can contain binaries built from earlier source version depending on the setting of "IGNORE_CRUFT"
- Britney refers to these as "${SOURCE_NAME}"
- "binary migration": An update of binary packages on a given architecture to an existing source package in the target suite.
- Two common cases: Built for the first time on a new architecture and binNMUs
- Britney refers to all cases of these as "${SOURCE_NAME}/${ARCHITECTURE}"
- "removal item": A removal of a source or binary package.
- Note that it is only possible to trigger "source" removals via hints. Binary removals are items generated by Britney to clean up the target suite.
- Britney refers to these as "-${SOURCE_NAME}" or "-${BINARY_NAME}/${ARCHITECTURE}" depending on the case.
Migration rules (excuses/policies)
Britney applies a number of policies to migration items before attempting to migrate them to the target suite. These policies can "reject" a package and prevent it from migrating. Some policies/built-in rules:
- Age policy: Lets source migrations age a bit before they are allowed to migrate
- Supports variable length based on package urgency
- RC Bug policy: Rejects packages with regressions in RC bugs
- Requires an external tool to keep the bug lists up to date
- Keeps architectures in sync: Source migrations updating existing packages only occur if architectures are up to date
- Can be configured to ignore certain architectures.