4.11 Moving to the Yocto Project 2.3 Release¶
This section provides migration information for moving to the Yocto Project 2.3 Release from the prior release.
4.11.1 Recipe-specific Sysroots¶
The OpenEmbedded build system now uses one sysroot per recipe to resolve long-standing issues with configuration script auto-detection of undeclared dependencies. Consequently, you might find that some of your previously written custom recipes are missing declared dependencies, particularly those dependencies that are incidentally built earlier in a typical build process and thus are already likely to be present in the shared sysroot in previous releases.
Consider the following:
Declare Build-Time Dependencies: Because of this new feature, you must explicitly declare all build-time dependencies for your recipe. If you do not declare these dependencies, they are not populated into the sysroot for the recipe.
Specify Pre-Installation and Post-Installation Native Tool Dependencies: You must specifically specify any special native tool dependencies of
pkg_postinstscripts by using the PACKAGE_WRITE_DEPS variable. Specifying these dependencies ensures that these tools are available if these scripts need to be run on the build host during the do_rootfs task.
As an example, see the
dbusrecipe. You will see that this recipe has a
systemctlif “systemd” is in DISTRO_FEATURES. In the example,
systemd-systemctl-nativeis added to
PACKAGE_WRITE_DEPS, which is also conditional on “systemd” being in
Examine Recipes that Use
SSTATEPOSTINSTFUNCS: You need to examine any recipe that uses
SSTATEPOSTINSTFUNCSand determine steps to take.
Functions added to
SSTATEPOSTINSTFUNCSare still called as they were in previous Yocto Project releases. However, since a separate sysroot is now being populated for every recipe and if existing functions being called through
SSTATEPOSTINSTFUNCSare doing relocation, then you will need to change these to use a post-installation script that is installed by a function added to SYSROOT_PREPROCESS_FUNCS.
For an example, see the
meta/classes/in the Yocto Project Source Repositories.
The SSTATEPOSTINSTFUNCS variable itself is now deprecated in favor of the do_populate_sysroot[postfuncs] task. Consequently, if you do still have any function or functions that need to be called after the sysroot component is created for a recipe, then you would be well advised to take steps to use a post installation script as described previously. Taking these steps prepares your code for when SSTATEPOSTINSTFUNCS is removed in a future Yocto Project release.
Specify the Sysroot when Using Certain External Scripts: Because the shared sysroot is now gone, the scripts
oe-run-nativehave been changed such that you need to specify which recipe’s STAGING_DIR_NATIVE is used.
You can find more information on how recipe-specific sysroots work in the “staging.bbclass” section.
Within the environment used to run build tasks, the environment variable
PATH is now sanitized such that the normal native binary paths
/usr/bin and so forth) are removed and a
directory containing symbolic links linking only to the binaries from
the host mentioned in the HOSTTOOLS and
HOSTTOOLS_NONFATAL variables is added
Consequently, any native binaries provided by the host that you need to call needs to be in one of these two variables at the configuration level.
Alternatively, you can add a native recipe (i.e.
provides the binary to the recipe’s DEPENDS
is not sanitized in the same way within
If it were, you would have difficulty running host tools for
development and debugging within the shell.
4.11.3 Changes to Scripts¶
The following changes to scripts took place:
oe-find-native-sysroot: The usage for the
oe-find-native-sysrootscript has changed to the following:
$ . oe-find-native-sysroot recipe
You must now supply a recipe for recipe as part of the command. Prior to the Yocto Project 2.3 release, it was not necessary to provide the script with the command.
oe-run-native: The usage for the
oe-run-nativescript has changed to the following:
$ oe-run-native native_recipe tool
You must supply the name of the native recipe and the tool you want to run as part of the command. Prior to the Yocto Project 2.3 release, it was not necessary to provide the native recipe with the command.
cleanup-workdirscript has been removed because the script was found to be deleting files it should not have, which lead to broken build trees. Rather than trying to delete portions of TMPDIR and getting it wrong, it is recommended that you delete
TMPDIRand have it restored from shared state (sstate) on subsequent builds.
wipe-sysrootscript has been removed as it is no longer needed with recipe-specific sysroots.
4.11.4 Changes to Functions¶
The previously deprecated
and related functions have been removed in favor of
d.setVar(), and so forth.
You need to fix any references to these old functions.
4.11.5 BitBake Changes¶
The following changes took place for BitBake:
BitBake’s Graphical Dependency Explorer UI Replaced: BitBake’s graphical dependency explorer UI
depexpwas replaced by
taskexp(“Task Explorer”), which provides a graphical way of exploring the
task-depends.dotfile. The data presented by Task Explorer is much more accurate than the data that was presented by
depexp. Being able to visualize the data is an often requested feature as standard
*.dotfile viewers cannot usual cope with the size of the
BitBake “-g” Output Changes: The
pn-depends.dotfiles as previously generated using the
bitbake -gcommand have been removed. A
recipe-depends.dotfile is now generated as a collapsed version of
The reason for this change is because
pn-depends.dotlargely date back to a time before task-based execution and do not take into account task-level dependencies between recipes, which could be misleading.
Mirror Variable Splitting Changes: Mirror variables including MIRRORS, PREMIRRORS, and SSTATE_MIRRORS can now separate values entirely with spaces. Consequently, you no longer need “\n”. BitBake looks for pairs of values, which simplifies usage. There should be no change required to existing mirror variable values themselves.
The Subversion (SVN) Fetcher Uses an “ssh” Parameter and Not an “rsh” Parameter: The SVN fetcher now takes an “ssh” parameter instead of an “rsh” parameter. This new optional parameter is used when the “protocol” parameter is set to “svn+ssh”. You can only use the new parameter to specify the
sshprogram used by SVN. The SVN fetcher passes the new parameter through the
SVN_SSHenvironment variable during the do_fetch task.
See the “Subversion (SVN) Fetcher (svn://)” section in the BitBake User Manual for additional information.
BB_SETSCENE_VERIFY_FUNCTION2Removed: Because the mechanism they were part of is no longer necessary with recipe-specific sysroots, the
BB_SETSCENE_VERIFY_FUNCTION2variables have been removed.
4.11.7 GPLv2 Versions of GPLv3 Recipes Moved¶
Older GPLv2 versions of GPLv3 recipes have moved to a separate
find meta-gplv2 layer in the OpenEmbedded layer index at
These relocated GPLv2 recipes do not receive the same level of maintenance as other core recipes. The recipes do not get security fixes and upstream no longer maintains them. In fact, the upstream community is actively hostile towards people that use the old versions of the recipes. Moving these recipes into a separate layer both makes the different needs of the recipes clearer and clearly identifies the number of these recipes.
The long-term solution might be to move to BSD-licensed replacements of the GPLv3 components for those that need to exclude GPLv3-licensed components from the target system. This solution will be investigated for future Yocto Project releases.
4.11.8 Package Management Changes¶
The following package management changes took place:
Smart package manager is replaced by DNF package manager. Smart has become unmaintained upstream, is not ported to Python 3.x. Consequently, Smart needed to be replaced. DNF is the only feasible candidate.
The change in functionality is that the on-target runtime package management from remote package feeds is now done with a different tool that has a different set of command-line options. If you have scripts that call the tool directly, or use its API, they need to be fixed.
For more information, see the DNF Documentation.
Rpm 5.x is replaced with Rpm 4.x. This is done for two major reasons:
DNF is API-incompatible with Rpm 5.x and porting it and maintaining the port is non-trivial.
Rpm 5.x itself has limited maintenance upstream, and the Yocto Project is one of the very few remaining users.
Berkeley DB 6.x is removed and Berkeley DB 5.x becomes the default:
Version 6.x of Berkeley DB has largely been rejected by the open source community due to its AGPLv3 license. As a result, most mainstream open source projects that require DB are still developed and tested with DB 5.x.
In OE-core, the only thing that was requiring DB 6.x was Rpm 5.x. Thus, no reason exists to continue carrying DB 6.x in OE-core.
createrepois replaced with
createrepo_cis the current incarnation of the tool that generates remote repository metadata. It is written in C as compared to
createrepo, which is written in Python.
createrepo_cis faster and is maintained.
Architecture-independent RPM packages are “noarch” instead of “all”.
This change was made because too many places in DNF/RPM4 stack already make that assumption. Only the filenames and the architecture tag has changed. Nothing else has changed in OE-core system, particularly in the allarch.bbclass class.
Signing of remote package feeds using
PACKAGE_FEED_SIGNis not currently supported. This issue will be fully addressed in a future Yocto Project release. See defect 11209 for more information on a solution to package feed signing with RPM in the Yocto Project 2.3 release.
OPKG now uses the libsolv backend for resolving package dependencies by default. This is vastly superior to OPKG’s internal ad-hoc solver that was previously used. This change does have a small impact on disk (around 500 KB) and memory footprint.
For further details on this change, see the commit message.
4.11.9 Removed Recipes¶
The following recipes have been removed:
linux-yocto 4.8: Version 4.8 has been removed. Versions 4.1 (LTSI), 4.4 (LTS), 4.9 (LTS/LTSI) and 4.10 are now present.
python-smartpm: Functionally replaced by
createrepo: Replaced by the
rpmresolve: No longer needed with the move to RPM 4 as RPM itself is used instead.
gstreamer: Removed the GStreamer Git version recipes as they have been stale.
1.10.x recipes are still present.
alsa-conf-base: Merged into
libasounddepended on both. Essentially, no way existed to install only one of these.
tremor: Moved to
meta-multimedia. Fixed-integer Vorbis decoding is not needed by current hardware. Thus, GStreamer’s ivorbis plugin has been disabled by default eliminating the need for the
tremorrecipe in OpenEmbedded-Core (OE-Core).
gummiboot: Replaced by
4.11.10 Wic Changes¶
The following changes have been made to Wic:
For more information on Wic, see the “Creating Partitioned Images Using Wic” section in the Yocto Project Development Tasks Manual.
Default Output Directory Changed: Wic’s default output directory is now the current directory by default instead of the unusual
The “-o” and “–outdir” options remain unchanged and are used to specify your preferred output directory if you do not want to use the default directory.
fsimage Plug-in Removed: The Wic fsimage plugin has been removed as it duplicates functionality of the rawcopy plugin.
4.11.11 QA Changes¶
The following QA checks have changed:
unsafe-references-in-binariesQA check, which was disabled by default, has now been removed. This check was intended to detect binaries in
/binthat link to libraries in
/usr/liband have the case where the user has
/usron a separate filesystem to
The removed QA check was buggy. Additionally,
/usrresiding on a separate partition from
/is now a rare configuration. Consequently,
file-rdepsQA check is now an error by default instead of a warning. Because it is an error instead of a warning, you need to address missing runtime dependencies.
4.11.12 Miscellaneous Changes¶
The following miscellaneous changes have occurred:
In this release, a number of recipes have been changed to ignore the
largefileDISTRO_FEATURES item, enabling large file support unconditionally. This feature has always been enabled by default. Disabling the feature has not been widely tested.
Future releases of the Yocto Project will remove entirely the ability to disable the largefile feature, which would make it unconditionally enabled everywhere.
If the DISTRO_VERSION value contains the value of the DATE variable, which is the default between Poky releases, the
DATEvalue is explicitly excluded from
/etc/issue.net, which is displayed at the login prompt, in order to avoid conflicts with Multilib enabled. Regardless, the
DATEvalue is inaccurate if the
base-filesrecipe is restored from shared state (sstate) rather than rebuilt.
If you need the build date recorded in
/etc/issue*or anywhere else in your image, a better method is to define a post-processing function to do it and have the function called from ROOTFS_POSTPROCESS_COMMAND. Doing so ensures the value is always up-to-date with the created image.
initscript now disables DSA host keys by default. This change is in line with the systemd service file, which supports RSA keys only, and with recent versions of OpenSSH, which deprecates DSA host keys.
The buildhistory class now correctly uses tabs as separators between all columns in
installed-package-sizes.txtin order to aid import into other tools.
USE_LDCONFIGvariable has been replaced with the “ldconfig”
DISTRO_FEATURESfeature. Distributions that previously set:
USE_LDCONFIG = "0"
should now instead use the following:
DISTRO_FEATURES_BACKFILL_CONSIDERED_append = " ldconfig"
The default value of COPYLEFT_LICENSE_INCLUDE now includes all versions of AGPL licenses in addition to GPL and LGPL.
The default list is not intended to be guaranteed as a complete safe list. You should seek legal advice based on what you are distributing if you are unsure.
Kernel module packages are now suffixed with the kernel version in order to allow module packages from multiple kernel versions to co-exist on a target system. If you wish to return to the previous naming scheme that does not include the version suffix, use the following:
KERNEL_MODULE_PACKAGE_SUFFIX = ""
*.lafiles is now enabled by default. The
*.lafiles are not actually needed on Linux and relocating them is an unnecessary burden.
If you need to preserve these
.lafiles (e.g. in a custom distribution), you must change INHERIT_DISTRO such that “remove-libtool” is not included in the value.
Extensible SDKs built for GCC 5+ now refuse to install on a distribution where the host GCC version is 4.8 or 4.9. This change resulted from the fact that the installation is known to fail due to the way the
uninativeshared state (sstate) package is built. See the uninative class for additional information.
All native and nativesdk recipes now use a separate
DISTRO_FEATURESvalue instead of sharing the value used by recipes for the target, in order to avoid unnecessary rebuilds.
FILESDIRvariable, which was previously deprecated and rarely used, has now been removed. You should change any recipes that set
FILESDIRto set FILESPATH instead.
MULTIMACH_HOST_SYSvariable has been removed as it is no longer needed with recipe-specific sysroots.