Yocto Package Installation Related Variables

Variables related to image/sdk installation
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PACKAGE_INSTALL: real package list to be installed on image
  export PACKAGE_INSTALL ?= "${IMAGE_INSTALL} ${ROOTFS_BOOTSTRAP_INSTALL} ${FEATURE_INSTALL}"

IMAGE_INSTALL: package list to be installed on image, take effect via the PACKAGE_INSTALL variable
  If PACKAGE_INSTALL is overridden in image recipe to not contain IMAGE_INSTALL, then IMAGE_INSTALL has no effect.

ROOTFS_BOOTSTRAP_INSTALL: package needed to bootstrap image
  default to run-postinsts, ROOTFS_BOOTSTRAP_INSTALL = "run-postinsts", take effect via PACKAGE_INSTALL variable

FEATURE_INSTALL: required packages which are bundled together and treated as image or distro features
  FEATURE_INSTALL = "${@' '.join(oe.packagegroup.required_packages(oe.data.typed_value('IMAGE_FEATURES', d), d))}"
  Its value is determined by the setting of IMAGE_FEATURES, the meta data related to IMAGE_FEATURES.
  e.g.
  FEATURE_PACKAGES_package-management = "${ROOTFS_PKGMANAGE}"
  And if IMAGE_FEATURES contain 'package-management', then ${ROOTFS_PKGMANAGE} would be installed.
  This var takes effect via PACKAGE_INSTALL variable.

PACKAGE_INSTALL_ATTEMPONLY: List of packages attempted to be installed. If a listed package fails to install, the build system does not generate an error.
  PACKAGE_INSTALL_ATTEMPTONLY ?= "${FEATURE_INSTALL_OPTIONAL}"

FEATURE_INSTALL_OPTIONAL: optional packages which are bundled together and treated as image or distro features
  FEATURE_INSTALL_OPTIONAL = "${@' '.join(oe.packagegroup.optional_packages(oe.data.typed_value('IMAGE_FEATURES', d), d))}"
  FEATURE_PACKAGES_foo = "bar"
  FEATURE_PACKAGES_foo[optional] = "1"
  Then if IMAGE_FEATURES contain 'foo', then FEATURE_INSTALL_OPTIONAL contain 'bar'.

IMAGE_INSTALL_COMPLEMENTARY: complementary packages like *-dev, *-dbg, etc
  IMAGE_INSTALL_COMPLEMENTARY = '${@complementary_globs("IMAGE_FEATURES", d)}'
  The variable is parsed in install_complementary in package_manager.py

LINGUAS_INSTALL: locale packages to install on image, set by the IMAGE_LINGUAS variable
  The packages specified by this var are treated as complementary packages.

TOOLCHAIN_HOST_TASK: packages installed in host part of SDK

TOOLCHAIN_HOST_TASK_ATTEMPTONLY: packages attempted to be installed in host part of SDK

TOOLCHAIN_TARGET_TASK: packages installed in target part of SDK

TOOLCHAIN_TARGET_TASK_ATTEMPTONLY: pacakges attempted to be installed in target part of SDK

SDKIMAGE_INSTALL_COMPLEMENTARY: complementary packages to be installed in SDK   meta/classes/populate_sdk_base.bbclass:SDKIMAGE_FEATURES ??= "dev-pkgs dbg-pkgs ${@bb.utils.contains('DISTRO_FEATURES', 'api-documentation', 'doc-pkgs', '', d)}"   meta/classes/populate_sdk_base.bbclass:SDKIMAGE_INSTALL_COMPLEMENTARY = '${@complementary_globs("SDKIMAGE_FEATURES", d)}'   meta/lib/oe/sdk.py:        self.target_pm.install_complementary(self.d.getVar('SDKIMAGE_INSTALL_COMPLEMENTARY'))