Reference: Architectures

snapcraft.yaml

The architectures how-to provides examples of how to use the architectures keyword.

core22

The root keyword architectures defines a list of build-on->build-for pairs with the following syntax:

architectures:
  - build-on: [<arch 1>, <arch 2>]
    build-for: [<arch 1>]
  - build-on: [<arch 3>]
    build-for: [<arch 4>]
    ...

See here for a list of supported architectures.

Data types

If the value is a single item, it can be written as a single element list or a scalar. For example:

architectures:
  - build-on: amd64
    build-for: arm64

is equivalent to:

architectures:
  - build-on: [amd64]
    build-for: [arm64]

Using a list is the recommended syntax. Scalars are not recommended.

build-on

The build-on field is required and can contain multiple architectures.

build-for

The build-for field is optional and should be a single element list. If it is not defined, the build-for will be set the build-on for each build in the build plan.

build-for: [all] is a special keyword to denote an architecture-independent snap. If the all keyword is used, no other build-on/build-for pairs can be defined. See this page to learn how to use the all keyword.

all cannot be used for build-on.

The same architecture cannot be defined in multiple build-for entries.

core20

The above syntax and rules for core22 apply for core20 except that run-on is used in place of build-for. Additionally, core20 supports multiple architectures in the run-on field, which will create multi-architecture snaps.

Shorthand format

As an alternative to the explicit format described above, core20 snaps support a shorthand format for simple build-on/run-on pairs. The following shorthand:

architectures: [amd64, arm64]

is equivalent to:

architectures:
  - build-on: [amd64]
    run-on: [amd64]
  - build-on: [arm64]
    run-on: [arm64]

The explicit and shorthand format cannot be mixed.

Project variables

core22

Project variable Description
CRAFT_ARCH_BUILD_FOR The architecture of the platform the snap is built for.
CRAFT_ARCH_BUILD_ON The architecture of the platform the snap is built on.
CRAFT_ARCH_TRIPLET_BUILD_FOR The architecture triplet of the platform the snap is built for.
CRAFT_ARCH_TRIPLET_BUILD_ON The architecture triplet of the platform the snap is built on.
CRAFT_ARCH_TRIPLET deprecated: use CRAFT_ARCH_TRIPLET_BUILD_FOR instead
CRAFT_TARGET_ARCH deprecated: use CRAFT_ARCH_BUILD_FOR instead

core20

core20 snaps use the terminology run-on in the architectures field in snapcraft.yaml. The project variables and documentation use the preferred term build-for.

Project variable Description
SNAPCRAFT_ARCH_BUILD_FOR The architecture of the platform the snap is built for.
SNAPCRAFT_ARCH_BUILD_ON The architecture of the platform the snap is built on.
SNAPCRAFT_ARCH_TRIPLET_BUILD_FOR The architecture triplet of the platform the snap is built for.
SNAPCRAFT_ARCH_TRIPLET_BUILD_ON The architecture triplet of the platform the snap is built on.
SNAPCRAFT_ARCH_TRIPLET The architecture triplet specified by --target-arch. If a target arch is not provided, then the architecture of the build-on platform is used.
SNAPCRAFT_TARGET_ARCH The architecture specified by --target-arch. If a target arch is not provided, then the architecture of the build-on platform is used.

SNAPCRAFT_ARCH_BUILD_FOR and SNAPCRAFT_ARCH_TRIPLET_BUILD_FOR are not available in either of the following scenarios:

  • when the build-for architecture is not in the list of supported architectures
  • when building a multi-architecture snap

Supported architectures

Supported locally

The following architectures can be used when building a snap locally.

  • amd64
  • arm64
  • armhf
  • i386
  • powerpc
  • ppc64el
  • riscv64
  • s390x

Supported by Launchpad

The following architectures are supported by Launchpad for remote building.

  • amd64
  • arm64
  • armhf
  • ppc64el
  • riscv64
  • s390x

Environment variables and command line arguments

core22

The command line argument --build-for=<arch> or environment variable SNAPCRAFT_BUILD_FOR=<arch> is used to build a single snap package for an architecture. It selects a single build-on->build-for pair from the build plan. It does not allow building a snap not defined by the build plan.

The command line argument takes priority over the environment variable.

See build plans for more information on how build plans are created.

core20

--target-arch=<arch> is used for cross-compiling in core20. It adds repositories for the target arch, which are used for stage-packages. The target arch does not need to be listed in the snapcraft.yaml architectures keyword.

The --target-arch argument can only be used in destructive mode and with --enable-experimental-target-arch or the environment variable SNAPCRAFT_ENABLE_EXPERIMENTAL_TARGET_ARCH.

The full usage is snapcraft --destructive-mode --enable-experimental-target-arch --target-arch=<arch>.


Last updated 2 months ago.