Release 3.0 (zeus)

This section provides migration information for moving to the Yocto Project 3.0 Release (codename “zeus”) from the prior release.

Init System Selection

Changing the init system manager previously required setting a number of different variables. You can now change the manager by setting the INIT_MANAGER variable and the corresponding include files (i.e. conf/distro/include/init-manager-*.conf). Include files are provided for four values: “none”, “sysvinit”, “systemd”, and “mdev-busybox”. The default value, “none”, for INIT_MANAGER should allow your current settings to continue working. However, it is advisable to explicitly set INIT_MANAGER.

LSB Support Removed

Linux Standard Base (LSB) as a standard is not current, and is not well suited for embedded applications. Support can be continued in a separate layer if needed. However, presently LSB support has been removed from the core.

As a result of this change, the poky-lsb derivative distribution configuration that was also used for testing alternative configurations has been replaced with a poky-altcfg distribution that has LSB parts removed.

Removed Recipes

The following recipes have been removed.

core-image-lsb-dev: Part of removed LSB support.
core-image-lsb: Part of removed LSB support.
core-image-lsb-sdk: Part of removed LSB support.
cve-check-tool: Functionally replaced by the cve-update-db recipe and cve-check class.
eglinfo: No longer maintained. eglinfo from mesa-demos is an adequate and maintained alternative.
gcc-8.3: Version 8.3 removed. Replaced by 9.2.
gnome-themes-standard: Only needed by gtk+ 2.x, which has been removed.
gtk+: GTK+ 2 is obsolete and has been replaced by gtk+3.
irda-utils: Has become obsolete. IrDA support has been removed from the Linux kernel in version 4.17 and later.
libnewt-python: libnewt Python support merged into main libnewt recipe.
libsdl: Replaced by newer libsdl2.
libx11-diet: Became obsolete.
libxx86dga: Removed obsolete client library.
libxx86misc: Removed. Library is redundant.
linux-yocto: Version 5.0 removed, which is now redundant (5.2 / 4.19 present).
lsbinitscripts: Part of removed LSB support.
lsb: Part of removed LSB support.
lsbtest: Part of removed LSB support.
openssl10: Replaced by newer openssl version 1.1.
packagegroup-core-lsb: Part of removed LSB support.
python-nose: Removed the Python 2.x version of the recipe.
python-numpy: Removed the Python 2.x version of the recipe.
python-scons: Removed the Python 2.x version of the recipe.
source-highlight: No longer needed.
stress: Replaced by stress-ng.
vulkan: Split into vulkan-loader, vulkan-headers, and vulkan-tools.
weston-conf: Functionality moved to weston-init.

Packaging Changes

The following packaging changes have occurred.

The Epiphany browser has been dropped from packagegroup-self-hosted as it has not been needed inside build-appliance-image for quite some time and was causing resource problems.
libcap-ng Python support has been moved to a separate libcap-ng-python recipe to streamline the build process when the Python bindings are not needed.
libdrm now packages the file amdgpu.ids into a separate libdrm-amdgpu package.
python3: The runpy module is now in the python3-core package as it is required to support the common “python3 -m” command usage.
distcc now provides separate distcc-client and distcc-server packages as typically one or the other are needed, rather than both.
python*-setuptools recipes now separately package the pkg_resources module in a python-pkg-resources / python3-pkg-resources package as the module is useful independent of the rest of the setuptools package. The main python-setuptools / python3-setuptools package depends on this new package so you should only need to update dependencies unless you want to take advantage of the increased granularity.

CVE Checking

cve-check-tool has been functionally replaced by a new cve-update-db recipe and functionality built into the cve-check class. The result uses NVD JSON data feeds rather than the deprecated XML feeds that cve-check-tool was using, supports CVSSv3 scoring, and makes other improvements.

Additionally, the CVE_CHECK_CVE_WHITELIST variable has been replaced by CVE_CHECK_WHITELIST (replaced by CVE_CHECK_IGNORE in version 3.5).

Bitbake Changes

The following BitBake changes have occurred.

addtask statements now properly validate dependent tasks. Previously, an invalid task was silently ignored. With this change, the invalid task generates a warning.
Other invalid addtask and deltask usages now trigger these warnings: “multiple target tasks arguments with addtask / deltask”, and “multiple before/after clauses”.
The “multiconfig” prefix is now shortened to “mc”. “multiconfig” will continue to work, however it may be removed in a future release.
The bitbake -g command no longer generates a recipe-depends.dot file as the contents (i.e. a reprocessed version of task-depends.dot) were confusing.
The bb.build.FuncFailed exception, previously raised by bb.build.exec_func() when certain other exceptions have occurred, has been removed. The real underlying exceptions will be raised instead. If you have calls to bb.build.exec_func() in custom classes or tinfoil-using scripts, any references to bb.build.FuncFailed should be cleaned up.
Additionally, the bb.build.exec_func() no longer accepts the “pythonexception” parameter. The function now always raises exceptions. Remove this argument in any calls to bb.build.exec_func() in custom classes or scripts.
The BB_SETSCENE_VERIFY_FUNCTION2 variable is no longer used. In the unlikely event that you have any references to it, they should be removed.
The RunQueueExecuteScenequeue and RunQueueExecuteTasks events have been removed since setscene tasks are now executed as part of the normal runqueue. Any event handling code in custom classes or scripts that handles these two events need to be updated.
The arguments passed to functions used with BB_HASHCHECK_FUNCTION have changed. If you are using your own custom hash check function, see https://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=40a5e193c4ba45c928fccd899415ea56b5417725 for details.
Task specifications in BB_TASKDEPDATA and class implementations used in signature generator classes now use “<fn>:<task>” everywhere rather than the “.” delimiter that was being used in some places. This change makes it consistent with all areas in the code. Custom signature generator classes and code that reads BB_TASKDEPDATA need to be updated to use ‘:’ as a separator rather than ‘.’.

Sanity Checks

The following sanity check changes occurred.

SRC_URI is now checked for usage of two problematic items:
- “${PN}” prefix/suffix use - Warnings always appear if ${PN} is used. You must fix the issue regardless of whether multiconfig or anything else that would cause prefixing/suffixing to happen.
- Github archive tarballs - these are not guaranteed to be stable. Consequently, it is likely that the tarballs will be refreshed and thus the SRC_URI checksums will fail to apply. It is recommended that you fetch either an official release tarball or a specific revision from the actual Git repository instead.
Either one of these items now trigger a warning by default. If you wish to disable this check, remove src-uri-bad from WARN_QA.
The file-rdeps runtime dependency check no longer expands RDEPENDS recursively as there is no mechanism to ensure they can be fully computed, and thus races sometimes result in errors either showing up or not. Thus, you might now see errors for missing runtime dependencies that were previously satisfied recursively. Here is an example: package A contains a shell script starting with #!/bin/bash but has no dependency on bash. However, package A depends on package B, which does depend on bash. You need to add the missing dependency or dependencies to resolve the warning.
Setting DEPENDS_${PN} anywhere (i.e. typically in a recipe) now triggers an error. The error is triggered because DEPENDS is not a package-specific variable unlike RDEPENDS. You should set DEPENDS instead.
systemd currently does not work well with the musl C library because only upstream officially supports linking the library with glibc. Thus, a warning is shown when building systemd in conjunction with musl.

Miscellaneous Changes

The following miscellaneous changes have occurred.

The gnome class has been removed because it now does very little. You should update recipes that previously inherited this class to do the following: inherit gnomebase gtk-icon-cache gconf mime
The meta/recipes-kernel/linux/linux-dtb.inc file has been removed. This file was previously deprecated in favor of setting KERNEL_DEVICETREE in any kernel recipe and only produced a warning. Remove any include or require statements pointing to this file.
TARGET_CFLAGS, TARGET_CPPFLAGS, TARGET_CXXFLAGS, and TARGET_LDFLAGS are no longer exported to the external environment. This change did not require any changes to core recipes, which is a good indicator that no changes will be required. However, if for some reason the software being built by one of your recipes is expecting these variables to be set, then building the recipe will fail. In such cases, you must either export the variable or variables in the recipe or change the scripts so that exporting is not necessary.
You must change the host distro identifier used in NATIVELSBSTRING to use all lowercase characters even if it does not contain a version number. This change is necessary only if you are not using uninative and SANITY_TESTED_DISTROS.
In the base-files recipe, writing the hostname into /etc/hosts and /etc/hostname is now done within the main do_install function rather than in the do_install_basefilesissue function. The reason for the change is because do_install_basefilesissue is more easily overridden without having to duplicate the hostname functionality. If you have done the latter (e.g. in a base-files bbappend), then you should remove it from your customized do_install_basefilesissue function.
The wic --expand command now uses commas to separate “key:value” pairs rather than hyphens.

Note

The wic command-line help is not updated.

You must update any scripts or commands where you use wic --expand with multiple “key:value” pairs.
UEFI image variable settings have been moved from various places to a central conf/image-uefi.conf. This change should not influence any existing configuration as the meta/conf/image-uefi.conf in the core metadata sets defaults that can be overridden in the same manner as before.
conf/distro/include/world-broken.inc has been removed. For cases where certain recipes need to be disabled when using the musl C library, these recipes now have COMPATIBLE_HOST_libc-musl set with a comment that explains why.