Django2.0手册:Django’s release process

Official releases¶

Since version 1.0, Django’s release numbering works as follows:

  • Versions are numbered in the form A.B or A.B.C.
  • A.B is the feature release version number. Each version will be mostly
    backwards compatible with the previous release. Exceptions to this rule will
    be listed in the release notes.
  • C is the patch release version number, which is incremented for bugfix
    and security releases. These releases will be 100% backwards-compatible with
    the previous patch release. The only exception is when a security or data
    loss issue can’t be fixed without breaking backwards-compatibility. If this
    happens, the release notes will provide detailed upgrade instructions.
  • Before a new feature release, we’ll make alpha, beta, and release candidate
    releases. These are of the form A.B alpha/beta/rc N, which means the
    Nth alpha/beta/release candidate of version A.B.

In git, each Django release will have a tag indicating its version number,
signed with the Django release key. Additionally, each release series has its
own branch, called stable/A.B.x, and bugfix/security releases will be
issued from those branches.

For more information about how the Django project issues new releases for
security purposes, please see our security policies.

Feature release
Feature releases (A.B, A.B+1, etc.) will happen roughly every eight months
— see release process for details. These releases will contain new
features, improvements to existing features, and such.
Patch release

Patch releases (A.B.C, A.B.C+1, etc.) will be issued as needed, to fix
bugs and/or security issues.

These releases will be 100% compatible with the associated feature release,
unless this is impossible for security reasons or to prevent data loss.
So the answer to “should I upgrade to the latest patch release?” will always
be “yes.”

Long-term support release

Certain feature releases will be designated as long-term support (LTS)
releases. These releases will get security and data loss fixes applied for
a guaranteed period of time, typically three years.

See the download page for the releases that have been designated for
long-term support.

Release cadence¶

Starting with Django 2.0, version numbers will use a loose form of semantic
versioning
such that each version following an LTS will
bump to the next “dot zero” version. For example: 2.0, 2.1, 2.2 (LTS), 3.0,
3.1, 3.2 (LTS), etc.

SemVer makes it easier to see at a glance how compatible releases are with each
other. It also helps to anticipate when compatibility shims will be removed.
It’s not a pure form of SemVer as each feature release will continue to have a
few documented backwards incompatibilities where a deprecation path isn’t
possible or not worth the cost. Also, deprecations started in an LTS release
(X.2) will be dropped in a non-dot-zero release (Y.1) to accommodate our policy
of keeping deprecation shims for at least two feature releases. Read on to the
next section for an example.

Deprecation policy¶

A feature release may deprecate certain features from previous releases. If a
feature is deprecated in feature release A.x, it will continue to work in all
A.x versions (for all versions of x) but raise warnings. Deprecated features
will be removed in the B.0 release, or B.1 for features deprecated in the last
A.x feature release to ensure deprecations are done over at least 2 feature
releases.

So, for example, if we decided to start the deprecation of a function in
Django 4.2:

  • Django 4.2 will contain a backwards-compatible replica of the function which
    will raise a RemovedInDjango51Warning.
  • Django 5.0 (the version that follows 4.2) will still contain the
    backwards-compatible replica.
  • Django 5.1 will remove the feature outright.

The warnings are silent by default. You can turn on display of these warnings
with the python -Wd option.

A more generic example:

  • X.0
  • X.1
  • X.2 LTS
  • Y.0: Drop deprecation shims added in X.0 and X.1.
  • Y.1: Drop deprecation shims added in X.2.
  • Y.2 LTS: No deprecation shims dropped (while Y.0 is no longer supported,
    third-party apps need to maintain compatibility back to X.2 LTS to ease
    LTS to LTS upgrades).
  • Z.0: Drop deprecation shims added in Y.0 and Y.1.

Supported versions¶

At any moment in time, Django’s developer team will support a set of releases to
varying levels. See the supported versions section of the download
page for the current state of support for each version.

  • The current development master will get new features and bug fixes
    requiring non-trivial refactoring.

  • Patches applied to the master branch must also be applied to the last feature
    release branch, to be released in the next patch release of that feature
    series, when they fix critical problems:

    • Security issues.
    • Data loss bugs.
    • Crashing bugs.
    • Major functionality bugs in new features of the latest stable release.
    • Regressions from older versions of Django.

    The rule of thumb is that fixes will be backported to the last feature
    release for bugs that would have prevented a release in the first place
    (release blockers).

  • Security fixes and data loss bugs will be applied to the current master, the
    last two feature release branches, and any other supported long-term
    support release branches.

  • Documentation fixes generally will be more freely backported to the last
    release branch. That’s because it’s highly advantageous to have the docs for
    the last release be up-to-date and correct, and the risk of introducing
    regressions is much less of a concern.

As a concrete example, consider a moment in time halfway between the release of
Django 5.1 and 5.2. At this point in time:

  • Features will be added to development master, to be released as Django 5.2.
  • Critical bug fixes will be applied to the stable/5.1.x branch, and
    released as 5.1.1, 5.1.2, etc.
  • Security fixes and bug fixes for data loss issues will be applied to
    master and to the stable/5.1.x, stable/5.0.x, and
    stable/4.2.x (LTS) branches. They will trigger the release of 5.1.1,
    5.0.5, 4.2.8, etc.
  • Documentation fixes will be applied to master, and, if easily backported, to
    the latest stable branch, 5.1.x.

Release process¶

Django uses a time-based release schedule, with feature releases every eight
months or so.

After each feature release, the release manager will announce a timeline for
the next feature release.

Release cycle¶

Each release cycle consists of three parts:

Phase one: feature proposal

The first phase of the release process will include figuring out what major
features to include in the next version. This should include a good deal of
preliminary work on those features — working code trumps grand design.

Major features for an upcoming release will be added to the wiki roadmap page,
e.g. https://code.djangoproject.com/wiki/Version1.11Roadmap.

Phase two: development

The second part of the release schedule is the “heads-down” working period.
Using the roadmap produced at the end of phase one, we’ll all work very hard to
get everything on it done.

At the end of phase two, any unfinished features will be postponed until the
next release.

Phase two will culminate with an alpha release. At this point, the
stable/A.B.x branch will be forked from master.

Phase three: bugfixes

The last part of a release cycle is spent fixing bugs — no new features will
be accepted during this time. We’ll try to release a beta release one month
after the alpha and a release candidate one month after the beta.

The release candidate marks the string freeze, and it happens at least two
weeks before the final release. After this point, new translatable strings
must not be added.

During this phase, committers will be more and more conservative with
backports, to avoid introducing regressions. After the release candidate, only
release blockers and documentation fixes should be backported.

In parallel to this phase, master can receive new features, to be released
in the A.B+1 cycle.

Bug-fix releases¶

After a feature release (e.g. A.B), the previous release will go into bugfix
mode.

The branch for the previous feature release (e.g. stable/A.B-1.x) will
include bugfixes. Critical bugs fixed on master must also be fixed on the
bugfix branch; this means that commits need to cleanly separate bug fixes from
feature additions. The developer who commits a fix to master will be
responsible for also applying the fix to the current bugfix branch.