### Bug Description On compatible hardware, where the vendor has not saved silicon to exclude 32bit support, one can use the `personality` system call to set the personality of a process to the 32bit sub-architecture of the 64bit architecture. Notably, 64bit kernels set such personality on 32bit programs automatically. This is perfect for running snapcraft on fast 64bit arm hardware, while using a lightweight 32bit container, so that one can build arm 32bit snaps natively, without having to add explicit support for full cross compilation. This fails, because snapcraft and the numerous `craft_` libraries don't universally understand this architecture mode, all while trying to understand architecture modes. On aarch64 kernel running 32bit userspace profile, or running with the 32bit personality flag set (see the setarch program for details) `uname -m` returns `armv8l`. ``` $ uname -m aarch64 $ setarch armv7l uname -m armv8l ``` Snapcraft should treat `armv8l` as an alias of `armv7l` across the board. I found ### To Reproduce On an arm64 system spawn an 32bit userspace container with lxd: ``` $ lxc launch ubuntu-daily:n/armhf ``` Then `lxc shell` into the container and install snapcraft: ``` # snap install --classic snapcraft ``` Finally run `--help`: ``` # snapcraft --help root@classic-sawfly:~# uname -a Linux classic-sawfly 6.14.0-1009-raspi #9-Ubuntu SMP PREEMPT_DYNAMIC Mon Jun 23 16:47:03 UTC 2025 armv8l armv8l armv8l GNU/Linux root@classic-sawfly:~# snapcraft --help [traceback] ``` ### Environment Ubuntu daily armhf on Ubuntu LTS aarch64 ### snapcraft.yaml ```yaml N/A ``` ### Relevant log output ```shell Traceback (most recent call last): File "/snap/snapcraft/15372/bin/snapcraft", line 5, in <module> from snapcraft.application import main File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/application.py", line 39, in <module> from snapcraft import cli, commands, errors, models, services, store File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/cli.py", line 33, in <module> from snapcraft import errors, store, utils File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/store/__init__.py", line 22, in <module> from .client import StoreClientCLI File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/store/client.py", line 35, in <module> from snapcraft import __version__, errors, models, utils File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/models/__init__.py", line 26, in <module> from .project import ( File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/models/project.py", line 2236, in <module> class ArchitectureProject(models.CraftBaseModel, extra="ignore"): File "/snap/snapcraft/15372/lib/python3.12/site-packages/snapcraft/models/project.py", line 2240, in ArchitectureProject default=[str(DebianArchitecture.from_host())], ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/snap/snapcraft/15372/lib/python3.12/site-packages/craft_platforms/_architectures.py", line 64, in from_host return cls.from_machine(platform.machine()) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/snap/snapcraft/15372/lib/python3.12/site-packages/craft_platforms/_architectures.py", line 59, in from_machine return cls(_ARCH_TRANSLATIONS_PLATFORM_TO_DEB.get(arch.lower(), arch.lower())) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/snap/snapcraft/current/usr/lib/python3.12/enum.py", line 757, in __call__ return cls.__new__(cls, value) ^^^^^^^^^^^^^^^^^^^^^^^ File "/snap/snapcraft/current/usr/lib/python3.12/enum.py", line 1171, in __new__ raise ve_exc ValueError: 'armv8l' is not a valid DebianArchitecture ``` ### Additional context _No response_