Step execution environment

Craft-parts defines the following environment for use during step processing and execution of user-defined scriptlets:

Variable Name	Description
CRAFT_ARCH_TRIPLET_BUILD_FOR	The architecture triplet of the build target. For example: x86_64-linux-gnu riscv64-linux-gnu
CRAFT_ARCH_TRIPLET_BUILD_ON	The architecture triplet of the host running the build. For example: x86_64-linux-gnu riscv64-linux-gnu
CRAFT_ARCH_BUILD_FOR	The architecture of the build target. For example: amd64 riscv64
CRAFT_ARCH_BUILD_ON	The architecture of the build target. For example: amd64 riscv64
CRAFT_PARALLEL_BUILD_COUNT	The maximum number of concurrent build jobs to execute.
CRAFT_PART_NAME	The name of the part currently being processed.
CRAFT_PART_SRC	The path to the part source directory. This is where sources are located after the PULL step.
CRAFT_PART_SRC_WORK	The path to the part source subdirectory, if any. Defaults to the part source directory.
CRAFT_PART_BUILD	The path to the part build directory. This is where parts are built during the BUILD step.
CRAFT_PART_BUILD_WORK	The path to the part build subdirectory in case of out-of-tree builds. Defaults to the part source directory.
CRAFT_PART_INSTALL	The path to the part install directory. This is where built artefacts are installed after the BUILD step.
CRAFT_OVERLAY	(If overlays are enabled) The path to the part’s layer directory during the OVERLAY step.
CRAFT_STAGE	The path to the project’s staging directory. This is where installed artefacts are migrated during the STAGE step.
CRAFT_PRIME	The path to the final primed payload directory after the PRIME step.

The following environment variables are also included, but are deprecated:

Variable Name	Description
CRAFT_ARCH_TRIPLET	The machine-vendor-os platform triplet definition. Use CRAFT_ARCH_TRIPLET_BUILD_ON or CRAFT_ARCH_TRIPLET_BUILD_FOR instead.
CRAFT_TARGET_ARCH	The architecture of the build target. Use CRAFT_ARCH_BUILD_FOR instead.

Some standard environment variables are also modified during parts execution steps.

PATH

Several paths are prepended to PATH during step execution, allowing staged executables from previous parts as well as already-built executables from the current path to be executed without calling their full path. The paths are only added to PATH if they exist. These paths are, in order:

• $CRAFT_PART_INSTALL/usr/sbin

• $CRAFT_PART_INSTALL/usr/bin

• $CRAFT_PART_INSTALL/sbin

• $CRAFT_PART_INSTALL/bin

• $CRAFT_STAGE/usr/sbin

• $CRAFT_STAGE/usr/bin

• $CRAFT_STAGE/sbin

• $CRAFT_STAGE/bin

CPPFLAGS, CFLAGS, CXXFLAGS

Each of these variables is set with a series of -isystem parameters to add the following include paths to most C and C++ compilers, if they exist:

• $CRAFT_PART_INSTALL/include

• $CRAFT_PART_INSTALL/usr/include

• $CRAFT_PART_INSTALL/include/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_PART_INSTALL/usr/include/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_STAGE/include

• $CRAFT_STAGE/usr/include

• $CRAFT_STAGE/include/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_STAGE/usr/include/$CRAFT_ARCH_TRIPLET_BUILD_FOR

LDFLAGS

LDFLAGS gets set with -L<directory> parameters for linkers to include the following library paths when linking, if the paths exist:

• $CRAFT_PART_INSTALL/lib

• $CRAFT_PART_INSTALL/usr/lib

• $CRAFT_PART_INSTALL/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_PART_INSTALL/usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_STAGE/lib

• $CRAFT_STAGE/usr/lib

• $CRAFT_STAGE/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR

• $CRAFT_STAGE/usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR

PKG_CONFIG_PATH

PKG_CONFIG_PATH is set so pkg-config will check the following extra paths, if they exist:

• $CRAFT_PART_INSTALL/lib/pkgconfig

• $CRAFT_PART_INSTALL/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_PART_INSTALL/usr/lib/pkgconfig

• $CRAFT_PART_INSTALL/usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_PART_INSTALL/usr/share/pkgconfig

• $CRAFT_PART_INSTALL/usr/local/lib/pkgconfig

• $CRAFT_PART_INSTALL/usr/local/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_PART_INSTALL/usr/local/share/pkgconfig

• $CRAFT_STAGE/lib/pkgconfig

• $CRAFT_STAGE/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_STAGE/usr/lib/pkgconfig

• $CRAFT_STAGE/usr/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_STAGE/usr/share/pkgconfig

• $CRAFT_STAGE/usr/local/lib/pkgconfig

• $CRAFT_STAGE/usr/local/lib/$CRAFT_ARCH_TRIPLET_BUILD_FOR/pkgconfig

• $CRAFT_STAGE/usr/local/share/pkgconfig

Plugin variables

A part’s plugin can add its own set of environment variables or expand on build-related flags.

The build-environment key can be used to either override the default environment variables or define new ones. The following example overrides default flags and searches for libraries in a non-standard path:

parts:
  hello-part:
    source: gnu-hello.tar.gz
    plugin: autotools
    build-environment:
      - CFLAGS: "$CFLAGS -O3"  # add -O3 to the existing flags
      - LDFLAGS: "-L$CRAFT_STAGE/non-standard/lib"