.. SPDX-License-Identifier: CC-BY-SA-2.0-UK

.. |yocto-codename| replace:: walnascar
.. |yocto-ver| replace:: 5.2
.. Note: anchors id below cannot contain substitutions so replace them with the
   value of |yocto-ver| above.

Release |yocto-ver| (|yocto-codename|)
======================================

Migration notes for |yocto-ver| (|yocto-codename|)
--------------------------------------------------

This section provides migration information for moving to the Yocto
Project |yocto-ver| Release (codename "|yocto-codename|") from the prior release.

``debug-tweaks`` removed from :term:`IMAGE_FEATURES`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``debug-tweaks`` image feature is now removed because it was too vague about
what it achieved: an image on which the ``root`` user can login without a
password.

To achieve the same result, the features previously added by ``debug-tweaks``
should be manually added to the :term:`IMAGE_FEATURES` variable. These are:

-  ``allow-empty-password``
-  ``allow-root-login``
-  ``empty-root-password``
-  ``post-install-logging``

Such a statement would be::

   IMAGE_FEATURES += "allow-empty-password allow-root-login empty-root-password post-install-logging"

See the list of available image features in the :ref:`ref-features-image`
section of the Yocto Project Reference Manual.

Supported kernel versions
~~~~~~~~~~~~~~~~~~~~~~~~~

The :term:`OLDEST_KERNEL` setting is XXX in this release, meaning that
out the box, older kernels are not supported. See :ref:`4.3 migration notes
<migration-4.3-supported-kernel-versions>` for details.

Supported distributions
~~~~~~~~~~~~~~~~~~~~~~~

Compared to the previous releases, running BitBake is supported on new
GNU/Linux distributions:

On the other hand, some earlier distributions are no longer supported:

See :ref:`all supported distributions <system-requirements-supported-distros>`.

Go language changes
~~~~~~~~~~~~~~~~~~~

Rust language changes
~~~~~~~~~~~~~~~~~~~~~

-  Recipes inheriting the :ref:`ref-classes-cargo` do not install libraries by
   default anymore. This behavior can be controlled by the
   :term:`CARGO_INSTALL_LIBRARIES` variable.

systemd changes
~~~~~~~~~~~~~~~

-  Support for ``split-usr`` and ``unmerged-usr`` are now removed after Systemd
   was updated to version 255. This option allowed installing Systemd in a
   system where directories such as ``/lib``, ``/sbin`` or ``/bin`` are *not*
   merged into ``/usr``.

   As a consequence, the ``systemd`` recipe no longer contains the ``usrmerge``
   :term:`PACKAGECONFIG` option as it is now implied by default.

Recipe changes
~~~~~~~~~~~~~~

Removed variables
~~~~~~~~~~~~~~~~~

The following variables have been removed:

-  ``PACKAGE_SNAP_LIB_SYMLINKS``: related to an unmaintained and obsolete
   "micro" :term:`distro <DISTRO>`.

-  ``SETUPTOOLS_INSTALL_ARGS``: obsolete and unused variable.

-  ``BB_DANGLINGAPPENDS_WARNONLY``: support for only warning the user when a
   ``.bbappend`` file doesn't apply to the original recipe has been dropped. See
   the :ref:`dev-manual/layers:Appending Other Layers Metadata With Your Layer`
   section of the Yocto Project Development Tasks Manual for alternatives to
   this variable.

Removed recipes
~~~~~~~~~~~~~~~

The following recipes have been removed in this release:

-  ``liburi-perl``: moved to :oe_git:`meta-perl </meta-openembedded/tree/meta-perl>`.
-  ``python3-isodate``: moved to :oe_git:`meta-python </meta-openembedded/tree/meta-python>`.
-  ``python3-iniparse``: removed as there are no consumers of this recipe in
   :oe_git:`openembedded-core </openembedded-core>` or :oe_git:`meta-openembedded </meta-openembedded>`.

Removed classes
~~~~~~~~~~~~~~~

The following classes have been removed in this release:

-  ``migrate_localcount.bbclass``: obsolete class for which code was already
   removed in 2012.

Miscellaneous changes
~~~~~~~~~~~~~~~~~~~~~

-  :term:`ZSTD_COMPRESSION_LEVEL` is now a plain integer number instead of a dash-prefixed
   command-line option (e.g. it should be set to ``3`` rather than ``-3``).