1Release 3.4 (honister) 2====================== 3 4This section provides migration information for moving to the Yocto 5Project 3.4 Release (codename "honister") from the prior release. 6 7Override syntax changes 8----------------------- 9 10In this release, the ``:`` character replaces the use of ``_`` to 11refer to an override, most commonly when making a conditional assignment 12of a variable. This means that an entry like:: 13 14 SRC_URI_qemux86 = "file://somefile" 15 16now becomes:: 17 18 SRC_URI:qemux86 = "file://somefile" 19 20since ``qemux86`` is an override. This applies to any use of override 21syntax, so the following:: 22 23 SRC_URI_append = " file://somefile" 24 SRC_URI_append_qemux86 = " file://somefile2" 25 SRC_URI_remove_qemux86-64 = " file://somefile3" 26 SRC_URI_prepend_qemuarm = "file://somefile4 " 27 FILES_${PN}-ptest = "${bindir}/xyz" 28 IMAGE_CMD_tar = "tar" 29 BASE_LIB_tune-cortexa76 = "lib" 30 SRCREV_pn-bash = "abc" 31 BB_TASK_NICE_LEVEL_task-testimage = '0' 32 33would now become:: 34 35 SRC_URI:append = " file://somefile" 36 SRC_URI:append:qemux86 = " file://somefile2" 37 SRC_URI:remove:qemux86-64 = " file://somefile3" 38 SRC_URI:prepend:qemuarm = "file://somefile4 " 39 FILES:${PN}-ptest = "${bindir}/xyz" 40 IMAGE_CMD:tar = "tar" 41 BASE_LIB:tune-cortexa76 = "lib" 42 SRCREV:pn-bash = "abc" 43 BB_TASK_NICE_LEVEL:task-testimage = '0' 44 45This also applies to 46:ref:`variable queries to the datastore <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:functions for accessing datastore variables>`, 47for example using ``getVar`` and similar so ``d.getVar("RDEPENDS_${PN}")`` 48becomes ``d.getVar("RDEPENDS:${PN}")``. 49 50Whilst some of these are fairly obvious such as :term:`MACHINE` and :term:`DISTRO` 51overrides, some are less obvious, for example the packaging variables such as 52:term:`RDEPENDS`, :term:`FILES` and so on taking package names (e.g. ``${PN}``, 53``${PN}-ptest``) as overrides. These overrides are not always in 54:term:`OVERRIDES` but applied conditionally in specific contexts 55such as packaging. ``task-<taskname>`` is another context specific override, the 56context being specific tasks in that case. Tune overrides are another special 57case where some code does use them as overrides but some does not. We plan to try 58and make the tune code use overrides more consistently in the future. 59 60There are some variables which do not use override syntax which include the 61suffix to variables in ``layer.conf`` files such as :term:`BBFILE_PATTERN`, 62:term:`SRCREV`\ ``_xxx`` where ``xxx`` is a name from :term:`SRC_URI` and 63:term:`PREFERRED_VERSION`\ ``_xxx``. In particular, ``layer.conf`` suffixes 64may be the same as a :term:`DISTRO` override causing some confusion. We do 65plan to try and improve consistency as these issues are identified. 66 67To help with migration of layers, a script has been provided in OE-Core. 68Once configured with the overrides used by a layer, this can be run as:: 69 70 <oe-core>/scripts/contrib/convert-overrides.py <layerdir> 71 72.. note:: 73 74 Please read the notes in the script as it isn't entirely automatic and it isn't 75 expected to handle every case. In particular, it needs to be told which overrides 76 the layer uses (usually machine and distro names/overrides) and the result should 77 be carefully checked since it can be a little enthusiastic and will convert 78 references to ``_append``, ``_remove`` and ``_prepend`` in function and variable 79 names. 80 81For reference, this conversion is important as it allows BitBake to more reliably 82determine what is an override and what is not, as underscores are also used in 83variable names without intending to be overrides. This should allow us to proceed 84with other syntax improvements and simplifications for usability. It also means 85BitBake no longer has to guess and maintain large lookup lists just in case 86e.g. ``functionname`` in ``my_functionname`` is an override, and thus should improve 87efficiency. 88 89 90New host dependencies 91--------------------- 92 93The ``lz4c``, ``pzstd`` and ``zstd`` commands are now required to be 94installed on the build host to support LZ4 and Zstandard compression 95functionality. These are typically provided by ``lz4`` and ``zstd`` 96packages in most Linux distributions. Alternatively they are available 97as part of ``buildtools-tarball`` if your distribution does not provide 98them. For more information see 99:ref:`ref-manual/system-requirements:required packages for the build host`. 100 101 102Removed recipes 103--------------- 104 105The following recipes have been removed in this release: 106 107- ``assimp``: problematic from a licensing perspective and no longer 108 needed by anything else 109- ``clutter-1.0``: legacy component moved to meta-gnome 110- ``clutter-gst-3.0``: legacy component moved to meta-gnome 111- ``clutter-gtk-1.0``: legacy component moved to meta-gnome 112- ``cogl-1.0``: legacy component moved to meta-gnome 113- ``core-image-clutter``: removed along with clutter 114- ``linux-yocto``: removed version 5.4 recipes (5.14 and 5.10 still 115 provided) 116- ``mklibs-native``: not actively tested and upstream mklibs still 117 requires Python 2 118- ``mx-1.0``: obsolete (last release 2012) and isn't used by anything in 119 any known layer 120- ``packagegroup-core-clutter``: removed along with clutter 121 122 123Removed classes 124--------------- 125 126- ``clutter``: moved to meta-gnome along with clutter itself 127- ``image-mklibs``: not actively tested and upstream mklibs still 128 requires Python 2 129- ``meta``: no longer useful. Recipes that need to skip installing 130 packages should inherit ``nopackages`` instead. 131 132 133Prelinking disabled by default 134------------------------------ 135 136Recent tests have shown that prelinking works only when PIE is not 137enabled (see `here <https://rlbl.me/prelink-1>`__ and `here <https://rlbl.me/prelink-2>`__), 138and as PIE is both a desirable security feature, and the only 139configuration provided and tested by the Yocto Project, there is 140simply no sense in continuing to enable prelink. 141 142There's also a concern that no one is maintaining the code, and there 143are open bugs (including `this serious one <https://bugzilla.yoctoproject.org/show_bug.cgi?id=14429>`__). 144Given that prelink does intricate address arithmetic and rewriting 145of binaries the best option is to disable the feature. It is recommended 146that you consider disabling this feature in your own configuration if 147it is currently enabled. 148 149 150Virtual runtime provides 151------------------------ 152 153Recipes shouldn't use the ``virtual/`` string in :term:`RPROVIDES` and 154:term:`RDEPENDS` - it is confusing because ``virtual/`` has no special 155meaning in :term:`RPROVIDES` and :term:`RDEPENDS` (unlike in the 156corresponding build-time :term:`PROVIDES` and :term:`DEPENDS`). 157 158 159Tune files moved to architecture-specific directories 160----------------------------------------------------- 161 162The tune files found in ``conf/machine/include`` have now been moved 163into their respective architecture name directories under that same 164location; e.g. x86 tune files have moved into an ``x86`` subdirectory, 165MIPS tune files have moved into a ``mips`` subdirectory, etc. 166The ARM tunes have an extra level (``armv8a``, ``armv8m``, etc.) and 167some have been renamed to make them uniform with the rest of the tunes. 168See `this commit <http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=1d381f21f5f13aa0c4e1a45683ed656ebeedd37d>`__ 169for reference. 170 171If you have any references to tune files (e.g. in custom machine 172configuration files) they will need to be updated. 173 174 175Extensible SDK host extension 176----------------------------- 177 178For a normal SDK, some layers append to :term:`TOOLCHAIN_HOST_TASK` 179unconditionally which is fine, until the eSDK tries to override the 180variable to its own values. Instead of installing packages specified 181in this variable it uses native recipes instead - a very different 182approach. This has led to confusing errors when binaries are added 183to the SDK but not relocated. 184 185To avoid these issues, a new :term:`TOOLCHAIN_HOST_TASK_ESDK` variable has 186been created. If you wish to extend what is installed in the host 187portion of the eSDK then you will now need to set this variable. 188 189 190Package/recipe splitting 191------------------------ 192 193- ``perl-cross`` has been split out from the main ``perl`` recipe to 194 its own ``perlcross`` recipe for maintenance reasons. If you have 195 bbappends for the perl recipe then these may need extending. 196 197- The ``wayland`` recipe now packages its binaries in a 198 ``wayland-tools`` package rather than putting them into 199 ``wayland-dev``. 200 201- Xwayland has been split out of the xserver-xorg tree and thus is now 202 in its own ``xwayland`` recipe. If you need Xwayland in your image 203 then you may now need to add it explicitly. 204 205- The ``rpm`` package no longer has ``rpm-build`` in its :term:`RRECOMMENDS`; 206 if by chance you still need rpm package building functionality in 207 your image and you have not already done so then you should add 208 ``rpm-build`` to your image explicitly. 209 210- The Python ``statistics`` standard module is now packaged in its own 211 ``python3-statistics`` package instead of ``python3-misc`` as 212 previously. 213 214 215Image / SDK generation changes 216------------------------------ 217 218- Recursive dependencies on the ``do_build`` task are now disabled when 219 building SDKs. These are generally not needed; in the unlikely event 220 that you do encounter problems then it will probably be as a result of 221 missing explicit dependencies that need to be added. 222 223- Errors during "complementary" package installation (e.g. for ``*-dbg`` 224 and ``*-dev`` packages) during image construction are no longer 225 ignored. Historically some of these packages had installation problems, 226 that is no longer the case. In the unlikely event that you see errors 227 as a result, you will need to fix the installation/packaging issues. 228 229- When building an image, only packages that will be used in building 230 the image (i.e. the first entry in :term:`PACKAGE_CLASSES`) will be 231 produced if multiple package types are enabled (which is not a typical 232 configuration). If in your CI system you need to have the original 233 behaviour, use ``bitbake --runall build <target>``. 234 235- The ``-lic`` package is no longer automatically added to 236 :term:`RRECOMMENDS` for every other package when 237 :term:`LICENSE_CREATE_PACKAGE` is set to "1". If you wish all license 238 packages to be installed corresponding to packages in your image, then 239 you should instead add the new ``lic-pkgs`` feature to 240 :term:`IMAGE_FEATURES`. 241 242 243Miscellaneous 244------------- 245 246- Certificates are now properly checked when bitbake fetches sources 247 over HTTPS. If you receive errors as a result for your custom recipes, 248 you will need to use a mirror or address the issue with the operators 249 of the server in question. 250 251- ``avahi`` has had its GTK+ support disabled by default. If you wish to 252 re-enable it, set ``AVAHI_GTK = "gtk3"`` in a bbappend for the 253 ``avahi`` recipe or in your custom distro configuration file. 254 255- Setting the ``BUILD_REPRODUCIBLE_BINARIES`` variable to "0" no longer 256 uses a strangely old fallback date of April 2011, it instead disables 257 building reproducible binaries as you would logically expect. 258 259- Setting noexec/nostamp/fakeroot varflags to any value besides "1" will 260 now trigger a warning. These should be either set to "1" to enable, or 261 not set at all to disable. 262 263- The previously deprecated ``COMPRESS_CMD`` and 264 ``CVE_CHECK_CVE_WHITELIST`` variables have been removed. Use 265 ``CONVERSION_CMD`` and :term:`CVE_CHECK_WHITELIST` respectively 266 instead. 267 268- The obsolete ``oe_machinstall`` function previously provided in the 269 :ref:`utils <ref-classes-utils>` class has been removed. For 270 machine-specific installation it is recommended that you use the 271 built-in override support in the fetcher or overrides in general 272 instead. 273