django/docs/internals/release-process.txt

.. _internals-release-process:

========================
Django's release process
========================

.. _official-releases:

Official releases
=================

Django's release numbering works as follows:

    * Versions are numbered in the form ``A.B`` or ``A.B.C``.

    * ``A`` is the *major version* number, which is only incremented for major
      changes to Django, and these changes are not necessarily
      backwards-compatible. That is, code you wrote for Django 6.0 may break
      when we release Django 7.0.

    * ``B`` is the *minor version* number, which is incremented for large yet
      backwards compatible changes.  Code written for Django 6.4 will continue
      to work under Django 6.5.

    * ``C`` is the *micro version* number which, is incremented for bug and
      security fixes.  A new micro-release will always be 100%
      backwards-compatible with the previous micro-release.

    * In some cases, we'll make alpha, beta, or 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``.

An exception to this version numbering scheme is the pre-1.0 Django code.
There's no guarantee of backwards-compatibility until the 1.0 release.

In Subversion, each Django release will be tagged under ``tags/releases``.  If
it's necessary to release a bug fix release or a security release that doesn't
come from the trunk, we'll copy that tag to ``branches/releases`` to make the
bug fix release.

Major releases
--------------

Major releases (1.0, 2.0, etc.) will happen very infrequently (think "years",
not "months"), and will probably represent major, sweeping changes to Django.

Minor releases
--------------

Minor release (1.1, 1.2, etc.) will happen roughly every six months -- see
`release process`_, below for details. 

These releases will contain new features, improvements to existing features, and
such. A minor release may deprecate certain features from previous releases. If a
feature in version ``A.B`` is deprecated, it will continue to work in version
``A.B+1``. In version ``A.B+2``, use of the feature will raise a
``PendingDeprecationWarning`` but will continue to work. Version ``A.B+3`` will
remove the feature entirely. 

So, for example, if we decided to remove a function that existed in Django 1.0:

    * Django 1.1 will contain a backwards-compatible replica of the function
      which will raise a ``PendingDeprecationWarning``. This warning is silent
      by default; you need to explicitly turn on display of these warnings.

    * Django 1.2 will contain the backwards-compatible replica, but the warning
      will be promoted to a full-fledged ``DeprecationWarning``. This warning is
      *loud* by default, and will likely be quite annoying.
      
    * Django 1.3 will remove the feature outright.
    
Micro releases
--------------

Micro releases (1.0.1, 1.0.2, 1.1.1, etc.) will be issued at least once half-way
between minor releases, and probably more often as needed.

These releases will always be 100% compatible with the associated minor release
-- the answer to "should I upgrade to the latest micro release?" will always be
"yes."

Each minor release of Django will have a "release maintainer" appointed. This
person will be responsible for making sure that bug fixes are applied to both
trunk and the maintained micro-release branch. This person will also work with
the release manager to decide when to release the micro releases.

Supported versions
==================

At any moment in time, Django's developer team will support a set of releases to
varying levels:

    * The current development trunk will get new features and bug fixes
      requiring major refactoring.
    
    * All bug fixes applied to the trunk will also be applied to the last
      minor release, to be released as the next micro release.
      
    * Security fixes will be applied to the current trunk and the previous two
      minor releases.
      
As a concrete example, consider a moment in time halfway between the release of
Django 1.3 and 1.4. At this point in time:

    * Features will be added to development trunk, to be released as Django 1.4.
    
    * Bug fixes will be applied to a ``1.3.X`` branch, and released as 1.3.1,
      1.3.2, etc.
      
    * Security releases will be applied to trunk, a ``1.3.X`` branch and a
      ``1.2.X`` branch. Security fixes will trigger the release of of ``1.3.1``,
      ``1.2.1``, etc.

.. _release-process:

Release process
===============

Django uses a time-based release schedule, with minor (i.e. 1.1, 1.2, etc.)
releases every six months, or more, depending on features. 

After each previous release (and after a suitable cooling-off period of a week
or two), the core development team will examine the landscape and announce a
timeline for the next release. Most releases will be scheduled in the 6-9 month
range, but if we have bigger features to development we might schedule a longer
period to allow for more ambitious work.

Release cycle
-------------

Each release cycle will be split into three periods, each lasting roughly
one-third of the cycle:

Phase one: feature proposal
~~~~~~~~~~~~~~~~~~~~~~~~~~~

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

At the end of part one, the core developers will propose a feature list for the
upcoming release. This will be broken into:

* "Must-have": critical features that will delay the release if not finished
* "Maybe" features: that will be pushed to the next release if not finished
* "Not going to happen": features explicitly deferred to a later release.

Anything that hasn't got at least some work done by the end of the first third
isn't eligible for the next release; a design alone isn't sufficient.

Phase two: development
~~~~~~~~~~~~~~~~~~~~~~

The second third 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.

Longer release schedules will likely spend more than a third of the time in this
phase.

At the end of phase two, any unfinished "maybe" features will be postponed until
the next release. Though it shouldn't happen, any "must-have" features will
extend phase two, and thus postpone the final release.

Phase two will culminate with an alpha release.

Phase three: bugfixes
~~~~~~~~~~~~~~~~~~~~~

The last third of a release is spent fixing bugs -- no new features will be
accepted during this time. We'll release a beta release about halfway through,
and an rc complete with string freeze two weeks before the end of the schedule.

Bug-fix releases
----------------

After a minor release (i.e 1.1), the previous release will go into bug-fix mode. 

A branch will be created of the form ``branches/releases/1.0.X`` to track
bug-fixes to the previous release. When possible, bugs fixed on trunk must
*also* be fixed on the bug-fix branch; this means that commits need to cleanly
separate bug fixes from feature additions. The developer who commits a fix to 
trunk will be responsible for also applying the fix to the current bug-fix
branch.  Each bug-fix branch will have a maintainer who will work with the
committers to keep them honest on backporting bug fixes.

How this all fits together
--------------------------

Let's look at a hypothetical example for how this all first together. Imagine,
if you will, a point about halfway between 1.1 and 1.2. At this point,
development will be happening in a bunch of places:

    * On trunk, development towards 1.2 proceeds with small additions, bugs
      fixes, etc. being checked in daily.
      
    * On the branch "branches/releases/1.1.X", bug fixes found in the 1.1
      release are checked in as needed. At some point, this branch will be
      released as "1.1.1", "1.1.2", etc.

    * On the branch "branches/releases/1.0.X", security fixes are made if
      needed and released as "1.0.2", "1.0.3", etc.
    
    * On feature branches, development of major features is done. These
      branches will be merged into trunk before the end of phase two.