.. SPDX-License-Identifier: CC-BY-SA-2.0-UK Maintaining Build Output Quality ******************************** Many factors can influence the quality of a build. For example, if you upgrade a recipe to use a new version of an upstream software package or you experiment with some new configuration options, subtle changes can occur that you might not detect until later. Consider the case where your recipe is using a newer version of an upstream package. In this case, a new version of a piece of software might introduce an optional dependency on another library, which is auto-detected. If that library has already been built when the software is building, the software will link to the built library and that library will be pulled into your image along with the new software even if you did not want the library. The :ref:`ref-classes-buildhistory` class helps you maintain the quality of your build output. You can use the class to highlight unexpected and possibly unwanted changes in the build output. When you enable build history, it records information about the contents of each package and image and then commits that information to a local Git repository where you can examine the information. The remainder of this section describes the following: - :ref:`How you can enable and disable build history ` - :ref:`How to understand what the build history contains ` - :ref:`How to limit the information used for build history ` - :ref:`How to examine the build history from both a command-line and web interface ` Enabling and Disabling Build History ==================================== Build history is disabled by default. To enable it, add the following :term:`INHERIT` statement and set the :term:`BUILDHISTORY_COMMIT` variable to "1" at the end of your ``conf/local.conf`` file found in the :term:`Build Directory`:: INHERIT += "buildhistory" BUILDHISTORY_COMMIT = "1" Enabling build history as previously described causes the OpenEmbedded build system to collect build output information and commit it as a single commit to a local :ref:`overview-manual/development-environment:git` repository. .. note:: Enabling build history increases your build times slightly, particularly for images, and increases the amount of disk space used during the build. You can disable build history by removing the previous statements from your ``conf/local.conf`` file. Understanding What the Build History Contains ============================================= Build history information is kept in ``${``\ :term:`TOPDIR`\ ``}/buildhistory`` in the :term:`Build Directory` as defined by the :term:`BUILDHISTORY_DIR` variable. Here is an example abbreviated listing: .. image:: figures/buildhistory.png :align: center :width: 50% At the top level, there is a ``metadata-revs`` file that lists the revisions of the repositories for the enabled layers when the build was produced. The rest of the data splits into separate ``packages``, ``images`` and ``sdk`` directories, the contents of which are described as follows. Build History Package Information --------------------------------- The history for each package contains a text file that has name-value pairs with information about the package. For example, ``buildhistory/packages/i586-poky-linux/busybox/busybox/latest`` contains the following: .. code-block:: none PV = 1.22.1 PR = r32 RPROVIDES = RDEPENDS = glibc (>= 2.20) update-alternatives-opkg RRECOMMENDS = busybox-syslog busybox-udhcpc update-rc.d PKGSIZE = 540168 FILES = /usr/bin/* /usr/sbin/* /usr/lib/busybox/* /usr/lib/lib*.so.* \ /etc /com /var /bin/* /sbin/* /lib/*.so.* /lib/udev/rules.d \ /usr/lib/udev/rules.d /usr/share/busybox /usr/lib/busybox/* \ /usr/share/pixmaps /usr/share/applications /usr/share/idl \ /usr/share/omf /usr/share/sounds /usr/lib/bonobo/servers FILELIST = /bin/busybox /bin/busybox.nosuid /bin/busybox.suid /bin/sh \ /etc/busybox.links.nosuid /etc/busybox.links.suid Most of these name-value pairs correspond to variables used to produce the package. The exceptions are ``FILELIST``, which is the actual list of files in the package, and ``PKGSIZE``, which is the total size of files in the package in bytes. There is also a file that corresponds to the recipe from which the package came (e.g. ``buildhistory/packages/i586-poky-linux/busybox/latest``): .. code-block:: none PV = 1.22.1 PR = r32 DEPENDS = initscripts kern-tools-native update-rc.d-native \ virtual/i586-poky-linux-compilerlibs virtual/i586-poky-linux-gcc \ virtual/libc virtual/update-alternatives PACKAGES = busybox-ptest busybox-httpd busybox-udhcpd busybox-udhcpc \ busybox-syslog busybox-mdev busybox-hwclock busybox-dbg \ busybox-staticdev busybox-dev busybox-doc busybox-locale busybox Finally, for those recipes fetched from a version control system (e.g., Git), there is a file that lists source revisions that are specified in the recipe and the actual revisions used during the build. Listed and actual revisions might differ when :term:`SRCREV` is set to ${:term:`AUTOREV`}. Here is an example assuming ``buildhistory/packages/qemux86-poky-linux/linux-yocto/latest_srcrev``):: # SRCREV_machine = "38cd560d5022ed2dbd1ab0dca9642e47c98a0aa1" SRCREV_machine = "38cd560d5022ed2dbd1ab0dca9642e47c98a0aa1" # SRCREV_meta = "a227f20eff056e511d504b2e490f3774ab260d6f" SRCREV_meta ="a227f20eff056e511d504b2e490f3774ab260d6f" You can use the ``buildhistory-collect-srcrevs`` command with the ``-a`` option to collect the stored :term:`SRCREV` values from build history and report them in a format suitable for use in global configuration (e.g., ``local.conf`` or a distro include file) to override floating :term:`AUTOREV` values to a fixed set of revisions. Here is some example output from this command:: $ buildhistory-collect-srcrevs -a # all-poky-linux SRCREV:pn-ca-certificates = "07de54fdcc5806bde549e1edf60738c6bccf50e8" SRCREV:pn-update-rc.d = "8636cf478d426b568c1be11dbd9346f67e03adac" # core2-64-poky-linux SRCREV:pn-binutils = "87d4632d36323091e731eb07b8aa65f90293da66" SRCREV:pn-btrfs-tools = "8ad326b2f28c044cb6ed9016d7c3285e23b673c8" SRCREV_bzip2-tests:pn-bzip2 = "f9061c030a25de5b6829e1abf373057309c734c0" SRCREV:pn-e2fsprogs = "02540dedd3ddc52c6ae8aaa8a95ce75c3f8be1c0" SRCREV:pn-file = "504206e53a89fd6eed71aeaf878aa3512418eab1" SRCREV_glibc:pn-glibc = "24962427071fa532c3c48c918e9d64d719cc8a6c" SRCREV:pn-gnome-desktop-testing = "e346cd4ed2e2102c9b195b614f3c642d23f5f6e7" SRCREV:pn-init-system-helpers = "dbd9197569c0935029acd5c9b02b84c68fd937ee" SRCREV:pn-kmod = "b6ecfc916a17eab8f93be5b09f4e4f845aabd3d1" SRCREV:pn-libnsl2 = "82245c0c58add79a8e34ab0917358217a70e5100" SRCREV:pn-libseccomp = "57357d2741a3b3d3e8425889a6b79a130e0fa2f3" SRCREV:pn-libxcrypt = "50cf2b6dd4fdf04309445f2eec8de7051d953abf" SRCREV:pn-ncurses = "51d0fd9cc3edb975f04224f29f777f8f448e8ced" SRCREV:pn-procps = "19a508ea121c0c4ac6d0224575a036de745eaaf8" SRCREV:pn-psmisc = "5fab6b7ab385080f1db725d6803136ec1841a15f" SRCREV:pn-ptest-runner = "bcb82804daa8f725b6add259dcef2067e61a75aa" SRCREV:pn-shared-mime-info = "18e558fa1c8b90b86757ade09a4ba4d6a6cf8f70" SRCREV:pn-zstd = "e47e674cd09583ff0503f0f6defd6d23d8b718d3" # qemux86_64-poky-linux SRCREV_machine:pn-linux-yocto = "20301aeb1a64164b72bc72af58802b315e025c9c" SRCREV_meta:pn-linux-yocto = "2d38a472b21ae343707c8bd64ac68a9eaca066a0" # x86_64-linux SRCREV:pn-binutils-cross-x86_64 = "87d4632d36323091e731eb07b8aa65f90293da66" SRCREV_glibc:pn-cross-localedef-native = "24962427071fa532c3c48c918e9d64d719cc8a6c" SRCREV_localedef:pn-cross-localedef-native = "794da69788cbf9bf57b59a852f9f11307663fa87" SRCREV:pn-debianutils-native = "de14223e5bffe15e374a441302c528ffc1cbed57" SRCREV:pn-libmodulemd-native = "ee80309bc766d781a144e6879419b29f444d94eb" SRCREV:pn-virglrenderer-native = "363915595e05fb252e70d6514be2f0c0b5ca312b" SRCREV:pn-zstd-native = "e47e674cd09583ff0503f0f6defd6d23d8b718d3" .. note:: Here are some notes on using the ``buildhistory-collect-srcrevs`` command: - By default, only values where the :term:`SRCREV` was not hardcoded (usually when :term:`AUTOREV` is used) are reported. Use the ``-a`` option to see all :term:`SRCREV` values. - The output statements might not have any effect if overrides are applied elsewhere in the build system configuration. Use the ``-f`` option to add the ``forcevariable`` override to each output line if you need to work around this restriction. - The script does apply special handling when building for multiple machines. However, the script does place a comment before each set of values that specifies which triplet to which they belong as previously shown (e.g., ``i586-poky-linux``). Build History Image Information ------------------------------- The files produced for each image are as follows: - ``image-files:`` A directory containing selected files from the root filesystem. The files are defined by :term:`BUILDHISTORY_IMAGE_FILES`. - ``build-id.txt:`` Human-readable information about the build configuration and metadata source revisions. This file contains the full build header as printed by BitBake. - ``*.dot:`` Dependency graphs for the image that are compatible with ``graphviz``. - ``files-in-image.txt:`` A list of files in the image with permissions, owner, group, size, and symlink information. - ``image-info.txt:`` A text file containing name-value pairs with information about the image. See the following listing example for more information. - ``installed-package-names.txt:`` A list of installed packages by name only. - ``installed-package-sizes.txt:`` A list of installed packages ordered by size. - ``installed-packages.txt:`` A list of installed packages with full package filenames. .. note:: Installed package information is able to be gathered and produced even if package management is disabled for the final image. Here is an example of ``image-info.txt``: .. code-block:: none DISTRO = poky DISTRO_VERSION = 3.4+snapshot-a0245d7be08f3d24ea1875e9f8872aa6bbff93be USER_CLASSES = buildstats IMAGE_CLASSES = qemuboot qemuboot license_image IMAGE_FEATURES = debug-tweaks IMAGE_LINGUAS = IMAGE_INSTALL = packagegroup-core-boot speex speexdsp BAD_RECOMMENDATIONS = NO_RECOMMENDATIONS = PACKAGE_EXCLUDE = ROOTFS_POSTPROCESS_COMMAND = write_package_manifest; license_create_manifest; cve_check_write_rootfs_manifest; ssh_allow_empty_password; ssh_allow_root_login; postinst_enable_logging; rootfs_update_timestamp; write_image_test_data; empty_var_volatile; sort_passwd; rootfs_reproducible; IMAGE_POSTPROCESS_COMMAND = buildhistory_get_imageinfo ; IMAGESIZE = 9265 Other than ``IMAGESIZE``, which is the total size of the files in the image in Kbytes, the name-value pairs are variables that may have influenced the content of the image. This information is often useful when you are trying to determine why a change in the package or file listings has occurred. Using Build History to Gather Image Information Only ---------------------------------------------------- As you can see, build history produces image information, including dependency graphs, so you can see why something was pulled into the image. If you are just interested in this information and not interested in collecting specific package or SDK information, you can enable writing only image information without any history by adding the following to your ``conf/local.conf`` file found in the :term:`Build Directory`:: INHERIT += "buildhistory" BUILDHISTORY_COMMIT = "0" BUILDHISTORY_FEATURES = "image" Here, you set the :term:`BUILDHISTORY_FEATURES` variable to use the image feature only. Build History SDK Information ----------------------------- Build history collects similar information on the contents of SDKs (e.g. ``bitbake -c populate_sdk imagename``) as compared to information it collects for images. Furthermore, this information differs depending on whether an extensible or standard SDK is being produced. The following list shows the files produced for SDKs: - ``files-in-sdk.txt:`` A list of files in the SDK with permissions, owner, group, size, and symlink information. This list includes both the host and target parts of the SDK. - ``sdk-info.txt:`` A text file containing name-value pairs with information about the SDK. See the following listing example for more information. - ``sstate-task-sizes.txt:`` A text file containing name-value pairs with information about task group sizes (e.g. :ref:`ref-tasks-populate_sysroot` tasks have a total size). The ``sstate-task-sizes.txt`` file exists only when an extensible SDK is created. - ``sstate-package-sizes.txt:`` A text file containing name-value pairs with information for the shared-state packages and sizes in the SDK. The ``sstate-package-sizes.txt`` file exists only when an extensible SDK is created. - ``sdk-files:`` A folder that contains copies of the files mentioned in ``BUILDHISTORY_SDK_FILES`` if the files are present in the output. Additionally, the default value of ``BUILDHISTORY_SDK_FILES`` is specific to the extensible SDK although you can set it differently if you would like to pull in specific files from the standard SDK. The default files are ``conf/local.conf``, ``conf/bblayers.conf``, ``conf/auto.conf``, ``conf/locked-sigs.inc``, and ``conf/devtool.conf``. Thus, for an extensible SDK, these files get copied into the ``sdk-files`` directory. - The following information appears under each of the ``host`` and ``target`` directories for the portions of the SDK that run on the host and on the target, respectively: .. note:: The following files for the most part are empty when producing an extensible SDK because this type of SDK is not constructed from packages as is the standard SDK. - ``depends.dot:`` Dependency graph for the SDK that is compatible with ``graphviz``. - ``installed-package-names.txt:`` A list of installed packages by name only. - ``installed-package-sizes.txt:`` A list of installed packages ordered by size. - ``installed-packages.txt:`` A list of installed packages with full package filenames. Here is an example of ``sdk-info.txt``: .. code-block:: none DISTRO = poky DISTRO_VERSION = 1.3+snapshot-20130327 SDK_NAME = poky-glibc-i686-arm SDK_VERSION = 1.3+snapshot SDKMACHINE = SDKIMAGE_FEATURES = dev-pkgs dbg-pkgs BAD_RECOMMENDATIONS = SDKSIZE = 352712 Other than ``SDKSIZE``, which is the total size of the files in the SDK in Kbytes, the name-value pairs are variables that might have influenced the content of the SDK. This information is often useful when you are trying to determine why a change in the package or file listings has occurred. Examining Build History Information ----------------------------------- You can examine build history output from the command line or from a web interface. To see any changes that have occurred (assuming you have :term:`BUILDHISTORY_COMMIT` = "1"), you can simply use any Git command that allows you to view the history of a repository. Here is one method:: $ git log -p You need to realize, however, that this method does show changes that are not significant (e.g. a package's size changing by a few bytes). There is a command-line tool called ``buildhistory-diff``, though, that queries the Git repository and prints just the differences that might be significant in human-readable form. Here is an example:: $ poky/poky/scripts/buildhistory-diff . HEAD^ Changes to images/qemux86_64/glibc/core-image-minimal (files-in-image.txt): /etc/anotherpkg.conf was added /sbin/anotherpkg was added * (installed-package-names.txt): * anotherpkg was added Changes to images/qemux86_64/glibc/core-image-minimal (installed-package-names.txt): anotherpkg was added packages/qemux86_64-poky-linux/v86d: PACKAGES: added "v86d-extras" * PR changed from "r0" to "r1" * PV changed from "0.1.10" to "0.1.12" packages/qemux86_64-poky-linux/v86d/v86d: PKGSIZE changed from 110579 to 144381 (+30%) * PR changed from "r0" to "r1" * PV changed from "0.1.10" to "0.1.12" .. note:: The ``buildhistory-diff`` tool requires the ``GitPython`` package. Be sure to install it using Pip3 as follows:: $ pip3 install GitPython --user Alternatively, you can install ``python3-git`` using the appropriate distribution package manager (e.g. ``apt``, ``dnf``, or ``zipper``). To see changes to the build history using a web interface, follow the instruction in the ``README`` file :yocto_git:`here `. Here is a sample screenshot of the interface: .. image:: figures/buildhistory-web.png :width: 100%