.. _4.0_Upgrading:

Upgrading to Buildbot 4.0 (not released)
========================================

Upgrading a Buildbot instance from 3.x to 4.0 may require some work to achieve.

The recommended upgrade procedure is as follows:

  - Upgrade to the last released BuildBot version in 3.x series.

  - Remove usage of the deprecated APIs.
    All usages of deprecated APIs threw a deprecation warning at the point of use.
    If the code does not emit deprecation warnings, it's in a good shape in this regard.
    You may need to run the master on a real workload in order to force all deprecated code paths to be exercised.

  - Upgrade to the latest Buildbot 4.0.x release.

  - (Optional) Upgrade to newest Buildbot 4.x.
    The newest point release will contain bug fixes and functionality improvements.

Build status generators
-----------------------

The ``subject`` argument of ``BuildStatusGenerator`` and ``BuildSetStatusGenerator`` has been removed.
The equivalent is setting the ``subject`` argument of the message formatter.

Message formatters
------------------

The ``wantLogs`` argument to message formatters has been removed.
The equivalent is setting both ``want_logs`` and ``want_logs_content`` to the previous value of ``wantLogs``.

The ``wantSteps`` and ``wantProperties`` arguments have been renamed to ``want_steps`` and ``want_properties`` respectively.