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diff --git a/documentation/migration-guides/migration-4.0.rst b/documentation/migration-guides/migration-4.0.rst new file mode 100644 index 0000000000..0e9e741458 --- /dev/null +++ b/documentation/migration-guides/migration-4.0.rst @@ -0,0 +1,271 @@ +.. SPDX-License-Identifier: CC-BY-SA-2.0-UK + +Release 4.0 (kirkstone) +======================= + +Migration notes for 4.0 (kirkstone) +----------------------------------- + +This section provides migration information for moving to the Yocto +Project 4.0 Release (codename "kirkstone") from the prior release. + +.. _migration-4.0-inclusive-language: + +Inclusive language improvements +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To use more `inclusive language <https://inclusivenaming.org/>`__ +in the code and documentation, some variables have been renamed, and +some have been deleted where they are no longer needed. In many cases the +new names are also easier to understand. BitBake will stop with an error when +renamed or removed variables still exist in your recipes or configuration. + +Please note that the change applies also to environmental variables, so +make sure you use a fresh environment for your build. + +The following variables have changed their names: + +- ``BB_ENV_WHITELIST`` became :term:`BB_ENV_PASSTHROUGH` +- ``BB_ENV_EXTRAWHITE`` became :term:`BB_ENV_PASSTHROUGH_ADDITIONS` +- ``BB_HASHBASE_WHITELIST`` became :term:`BB_BASEHASH_IGNORE_VARS` +- ``BB_HASHCONFIG_WHITELIST`` became :term:`BB_HASHCONFIG_IGNORE_VARS` +- ``BB_HASHTASK_WHITELIST`` became ``BB_TASKHASH_IGNORE_TASKS`` +- ``BB_SETSCENE_ENFORCE_WHITELIST`` became ``BB_SETSCENE_ENFORCE_IGNORE_TASKS`` +- ``CVE_CHECK_PN_WHITELIST`` became :term:`CVE_CHECK_SKIP_RECIPE` +- ``CVE_CHECK_WHITELIST`` became :term:`CVE_CHECK_IGNORE` +- ``ICECC_USER_CLASS_BL`` became :term:`ICECC_CLASS_DISABLE` +- ``ICECC_SYSTEM_CLASS_BL`` became :term:`ICECC_CLASS_DISABLE` +- ``ICECC_USER_PACKAGE_WL`` became :term:`ICECC_RECIPE_ENABLE` +- ``ICECC_USER_PACKAGE_BL`` became :term:`ICECC_RECIPE_DISABLE` +- ``ICECC_SYSTEM_PACKAGE_BL`` became :term:`ICECC_RECIPE_DISABLE` +- ``LICENSE_FLAGS_WHITELIST`` became :term:`LICENSE_FLAGS_ACCEPTED` +- ``MULTI_PROVIDER_WHITELIST`` became :term:`BB_MULTI_PROVIDER_ALLOWED` +- ``PNBLACKLIST`` became :term:`SKIP_RECIPE` +- ``SDK_LOCAL_CONF_BLACKLIST`` became :term:`ESDK_LOCALCONF_REMOVE` +- ``SDK_LOCAL_CONF_WHITELIST`` became :term:`ESDK_LOCALCONF_ALLOW` +- ``SDK_INHERIT_BLACKLIST`` became :term:`ESDK_CLASS_INHERIT_DISABLE` +- ``SSTATE_DUPWHITELIST`` became ``SSTATE_ALLOW_OVERLAP_FILES`` +- ``SYSROOT_DIRS_BLACKLIST`` became :term:`SYSROOT_DIRS_IGNORE` +- ``UNKNOWN_CONFIGURE_WHITELIST`` became :term:`UNKNOWN_CONFIGURE_OPT_IGNORE` +- ``WHITELIST_<license>`` became :term:`INCOMPATIBLE_LICENSE_EXCEPTIONS` + +In addition, ``BB_STAMP_WHITELIST``, ``BB_STAMP_POLICY``, ``INHERIT_BLACKLIST``, +``TUNEABI``, ``TUNEABI_WHITELIST``, and ``TUNEABI_OVERRIDE`` have been removed. + +Many internal variable names have been also renamed accordingly. + +In addition, in the ``cve-check`` output, the CVE issue status ``Whitelisted`` +has been renamed to ``Ignored``. + +The :term:`BB_DISKMON_DIRS` variable value now uses the term ``HALT`` +instead of ``ABORT``. + +A :oe_git:`convert-variable-renames.py +</openembedded-core/tree/scripts/contrib/convert-variable-renames.py>` +script is provided to convert your recipes and configuration, +and also warns you about the use of problematic words. The script performs +changes and you need to review them before committing. An example warning +looks like:: + + poky/scripts/lib/devtool/upgrade.py needs further work at line 275 since it contains abort + +Fetching changes +~~~~~~~~~~~~~~~~ + +- Because of the uncertainty in future default branch names in git repositories, + it is now required to add a branch name to all URLs described + by ``git://`` and ``gitsm://`` :term:`SRC_URI` entries. For example:: + + SRC_URI = "git://git.denx.de/u-boot.git;branch=master" + + A :oe_git:`convert-srcuri </openembedded-core/tree/scripts/contrib/convert-srcuri.py>` + script to convert your recipes is available in :term:`OpenEmbedded-Core (OE-Core)` + and in :term:`Poky`. + +- Because of `GitHub dropping support for the git: + protocol <https://github.blog/2021-09-01-improving-git-protocol-security-github/>`__, + recipes now need to use ``;protocol=https`` at the end of GitHub + URLs. The same ``convert-srcuri`` script mentioned above can be used to convert + your recipes. + +- Network access from tasks is now disabled by default on kernels which support + this feature (on most recent distros such as CentOS 8 and Debian 11 onwards). + This means that tasks accessing the network need to be marked as such with the ``network`` + flag. For example:: + + do_mytask[network] = "1" + + This is allowed by default from :ref:`ref-tasks-fetch` but not from any of our other standard + tasks. Recipes shouldn't be accessing the network outside of :ref:`ref-tasks-fetch` as it + usually undermines fetcher source mirroring, image and licence manifests, software + auditing and supply chain security. + +License changes +~~~~~~~~~~~~~~~ + +- The ambiguous "BSD" license has been removed from the ``common-licenses`` directory. + Each recipe that fetches or builds BSD-licensed code should specify the proper + version of the BSD license in its :term:`LICENSE` value. + +- :term:`LICENSE` variable values should now use `SPDX identifiers <https://spdx.org/licenses/>`__. + If they do not, by default a warning will be shown. A + :oe_git:`convert-spdx-licenses.py </openembedded-core/tree/scripts/contrib/convert-spdx-licenses.py>` + script can be used to update your recipes. + +- :term:`INCOMPATIBLE_LICENSE` should now use `SPDX identifiers <https://spdx.org/licenses/>`__. + Additionally, wildcarding is now limited to specifically supported values - + see the :term:`INCOMPATIBLE_LICENSE` documentation for further information. + +- The ``AVAILABLE_LICENSES`` variable has been removed. This variable was a performance + liability and is highly dependent on which layers are added to the configuration, + which can cause signature issues for users. In addition the ``available_licenses()`` + function has been removed from the :ref:`ref-classes-license` class as + it is no longer needed. + +Removed recipes +~~~~~~~~~~~~~~~ + +The following recipes have been removed in this release: + +- ``dbus-test``: merged into main dbus recipe +- ``libid3tag``: moved to meta-oe - no longer needed by anything in OE-Core +- ``libportal``: moved to meta-gnome - no longer needed by anything in OE-Core +- ``linux-yocto``: removed version 5.14 recipes (5.15 and 5.10 still provided) +- ``python3-nose``: has not changed since 2016 upstream, and no longer needed by anything in OE-Core +- ``rustfmt``: not especially useful as a standalone recipe + +Python changes +~~~~~~~~~~~~~~ + +- ``distutils`` has been deprecated upstream in Python 3.10 and thus the ``distutils*`` + classes have been moved to ``meta-python``. Recipes that inherit the ``distutils*`` + classes should be updated to inherit ``setuptools*`` equivalents instead. + +- The Python package build process is now based on `wheels <https://pythonwheels.com/>`__. + The new Python packaging classes that should be used are + :ref:`ref-classes-python_flit_core`, :ref:`ref-classes-python_setuptools_build_meta` + and :ref:`ref-classes-python_poetry_core`. + +- The :ref:`ref-classes-setuptools3` class :ref:`ref-tasks-install` task now + installs the ``wheel`` binary archive. In current versions of ``setuptools`` the + legacy ``setup.py install`` method is deprecated. If the ``setup.py`` cannot be used + with wheels, for example it creates files outside of the Python module or standard + entry points, then :ref:`ref-classes-setuptools3_legacy` should + be used instead. + +Prelink removed +~~~~~~~~~~~~~~~ + +Prelink has been dropped by ``glibc`` upstream in 2.36. It already caused issues with +binary corruption, has a number of open bugs and is of questionable benefit +without disabling load address randomization and PIE executables. + +We disabled prelinking by default in the honister (3.4) release, but left it able +to be enabled if desired. However, without glibc support it cannot be maintained +any further, so all of the prelinking functionality has been removed in this release. +If you were enabling the ``image-prelink`` class in :term:`INHERIT`, :term:`IMAGE_CLASSES`, +:term:`USER_CLASSES` etc in your configuration, then you will need to remove the +reference(s). + +Reproducible as standard +~~~~~~~~~~~~~~~~~~~~~~~~ + +Reproducibility is now considered as standard functionality, thus the +``reproducible`` class has been removed and its previous contents merged into the +:ref:`ref-classes-base` class. If you have references in your configuration to +``reproducible`` in :term:`INHERIT`, :term:`USER_CLASSES` etc. then they should be +removed. + +Additionally, the ``BUILD_REPRODUCIBLE_BINARIES`` variable is no longer used. +Specifically for the kernel, if you wish to enable build timestamping functionality +that is normally disabled for reproducibility reasons, you can do so by setting +a new :term:`KERNEL_DEBUG_TIMESTAMPS` variable to "1". + +Supported host distribution changes +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- Support for :wikipedia:`AlmaLinux <AlmaLinux>` + hosts replacing :wikipedia:`CentOS <CentOS>`. + The following distribution versions were dropped: CentOS 8, Ubuntu 16.04 and Fedora 30, 31 and 32. + +- ``gcc`` version 7.5 is now required at minimum on the build host. For older + host distributions where this is not available, you can use the + :term:`buildtools-extended` tarball (easily installable using + ``scripts/install-buildtools``). + +:append/:prepend in combination with other operators +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The ``append``, ``prepend`` and ``remove`` operators can now only be combined with +``=`` and ``:=`` operators. To the exception of the ``append`` plus ``+=`` and +``prepend`` plus ``=+`` combinations, all combinations could be factored up to the +``append``, ``prepend`` or ``remove`` in the combination. This brought a lot of +confusion on how the override style syntax operators work and should be used. +Therefore, those combinations should be replaced by a single ``append``, +``prepend`` or ``remove`` operator without any additional change. +For the ``append`` plus ``+=`` (and ``prepend`` plus ``=+``) combinations, +the content should be prefixed (respectively suffixed) by a space to maintain +the same behavior. You can learn more about override style syntax operators +(``append``, ``prepend`` and ``remove``) in the BitBake documentation: +:ref:`bitbake-user-manual/bitbake-user-manual-metadata:appending and prepending (override style syntax)` +and :ref:`bitbake-user-manual/bitbake-user-manual-metadata:removal (override style syntax)`. + +Miscellaneous changes +~~~~~~~~~~~~~~~~~~~~~ + +- ``blacklist.bbclass`` is removed and the functionality moved to the + :ref:`ref-classes-base` class with a more descriptive + ``varflag`` variable named :term:`SKIP_RECIPE` which will use the `bb.parse.SkipRecipe()` + function. The usage remains the same, for example:: + + SKIP_RECIPE[my-recipe] = "Reason for skipping recipe" + +- :ref:`ref-classes-allarch` packagegroups can no longer depend on packages + which use :term:`PKG` renaming such as :ref:`ref-classes-debian`. Such packagegroups + recipes should be changed to avoid inheriting :ref:`ref-classes-allarch`. + +- The ``lnr`` script has been removed. ``lnr`` implemented the same behaviour as `ln --relative --symbolic`, + since at the time of creation `--relative` was only available in coreutils 8.16 + onwards which was too new for the older supported distros. Current supported host + distros have a new enough version of coreutils, so it is no longer needed. If you have + any calls to ``lnr`` in your recipes or classes, they should be replaced with + `ln --relative --symbolic` or `ln -rs` if you prefer the short version. + +- The ``package_qa_handle_error()`` function formerly in the :ref:`ref-classes-insane` + class has been moved and renamed - if you have any references in your own custom + classes they should be changed to ``oe.qa.handle_error()``. + +- When building ``perl``, Berkeley db support is no longer enabled by default, since + Berkeley db is largely obsolete. If you wish to reenable it, you can append ``bdb`` + to :term:`PACKAGECONFIG` in a ``perl`` bbappend or ``PACKAGECONFIG:pn-perl`` at + the configuration level. + +- For the ``xserver-xorg`` recipe, the ``xshmfence``, ``xmlto`` and ``systemd`` options + previously supported in :term:`PACKAGECONFIG` have been removed, as they are no + longer supported since the move from building it with autotools to meson in this release. + +- For the ``libsdl2`` recipe, various X11 features are now disabled by default (primarily + for reproducibility purposes in the native case) with options in :term:`EXTRA_OECMAKE` + within the recipe. These can be changed within a bbappend if desired. See the + ``libsdl2`` recipe for more details. + +- The ``cortexa72-crc`` and ``cortexa72-crc-crypto`` tunes have been removed since + the crc extension is now enabled by default for cortexa72. Replace any references to + these with ``cortexa72`` and ``cortexa72-crypto`` respectively. + +- The Python development shell (previously known as ``devpyshell``) feature has been + renamed to ``pydevshell``. To start it you should now run:: + + bitbake <target> -c pydevshell + +- The ``packagegroups-core-full-cmdline-libs`` packagegroup is no longer produced, as + libraries should normally be brought in via dependencies. If you have any references + to this then remove them. + +- The :term:`TOPDIR` variable and the current working directory are no longer modified + when parsing recipes. Any code depending on the previous behaviour will no longer + work - change any such code to explicitly use appropriate path variables instead. + +- In order to exclude the kernel image from the image rootfs, + :term:`RRECOMMENDS`\ ``:${KERNEL_PACKAGE_NAME}-base`` should be set instead of + :term:`RDEPENDS`\ ``:${KERNEL_PACKAGE_NAME}-base``. |