### Bug Description I tried to build the `pc-amd64-gadget-desktop` snap (version 22) for core desktop, but snapcraft 8.2.x, but it crashes with an error. Also tried with version 24 and it fails too, but doesn't crash. Instead, snapcraft 7.5.5 works like a charm. ### To Reproduce - Download the repository from `https://github.com/canonical/pc-amd64-gadget-desktop.git` - Change to branch `22` (or `24`; it fails in both. - Run `snapcraft` ### Environment I'm using LXD under Ubuntu 24.04 LTS. ### snapcraft.yaml ```shell name: pc-desktop version: '22-0.4' type: gadget build-base: core22 base: core22-desktop summary: PC gadget for generic devices description: | This gadget enables generic pc devices to work with Ubuntu Core Desktop confinement: strict grade: stable architectures: - build-on: amd64 build-for: amd64 icon: icon.png package-repositories: - type: apt ppa: ucdev/uc-staging-ppa hooks: prepare-device: environment: # If you are forking and building your own gadget: # define your model's API key here # See https://ubuntu.com/core/services/guide/serial-vault-overview # for instructions on how to generate an API key # DO NOT check this API key into a publicly accessible VCS MODEL_APIKEY: "" # Min version to support shim 15.7 # Using passthrough until LP#2019931 is fixed passthrough: assumes: - snapd2.59.3 parts: # Temporary workaround until pinning is supported by snapcraft pin-ucdev: plugin: nil override-pull: | # This is run before the pull step of grub part, so we make sure # we get the packages from the PPA. set -x cat <<'EOF' > /etc/apt/preferences.d/ucdev Package: * Pin: release LP-PPA-ucdev-uc-staging-ppa,a=jammy,n=jammy Pin: origin ppa.launchpad.net Pin-Priority: 1000 EOF mbr: source: . build-packages: - ubuntu-dev-tools plugin: make grub: after: [ pin-ucdev ] plugin: nil source: . build-packages: - ubuntu-dev-tools - grub-pc-bin - grub-common - sbsigntool stage-packages: - grub-efi-amd64-signed - shim-signed override-build: | set -x # Make sure we have signatures from the UC certificates sbverify --list "$CRAFT_PART_INSTALL"/usr/lib/shim/shimx64.efi.dualsigned | grep -E 'Canonical Ltd. Secure Boot Signing \(Ubuntu Core' sbverify --list "$CRAFT_PART_INSTALL"/usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed | grep -E 'Canonical Ltd. Secure Boot Signing \(Ubuntu Core' # grub.conf lets snapd identify grub as the bootloader on boot install -m 644 /dev/null "$CRAFT_PART_INSTALL"/grub.conf organize: usr/lib/shim/shimx64.efi.dualsigned: shim.efi.signed usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed: grubx64.efi prime: - shim.efi.signed - grubx64.efi - grub.conf extra: source: ./extra plugin: dump ``` ### Relevant log output ```shell With branch 24 it shows: `Unknown base 'core24-desktop'` With branch 22 it crashes with: Traceback (most recent call last): File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/application.py", line 361, in main return app.run() File "/snap/snapcraft/11722/lib/python3.10/site-packages/craft_application/application.py", line 488, in run dispatcher = self._get_dispatcher() File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/application.py", line 220, in _get_dispatcher raise errors.ClassicFallback() snapcraft.errors.ClassicFallback During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/models/project.py", line 651, in _providers_base return SNAPCRAFT_BASE_TO_PROVIDER_BASE[base] KeyError: 'core22-desktop' The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/snap/snapcraft/11722/bin/snapcraft", line 8, in <module> sys.exit(main()) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/application.py", line 364, in main return cli.run() File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/cli.py", line 222, in run _run_dispatcher(dispatcher, global_args) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/cli.py", line 194, in _run_dispatcher dispatcher.run() File "/snap/snapcraft/11722/lib/python3.10/site-packages/craft_cli/dispatcher.py", line 487, in run return self._loaded_command.run(self._parsed_command_args) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/commands/core22/lifecycle.py", line 265, in run super().run(parsed_args) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/commands/core22/lifecycle.py", line 138, in run parts_lifecycle.run(self.name, parsed_args) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/parts/lifecycle.py", line 104, in run project = models.Project.unmarshal(yaml_data_for_arch) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/models/project.py", line 876, in unmarshal project = Project(**data) File "pydantic/main.py", line 339, in pydantic.main.BaseModel.__init__ File "pydantic/main.py", line 1100, in pydantic.main.validate_model File "/snap/snapcraft/11722/lib/python3.10/site-packages/craft_application/models/project.py", line 178, in _validate_devel base_alias = cls._providers_base(base) File "/snap/snapcraft/11722/lib/python3.10/site-packages/snapcraft/models/project.py", line 653, in _providers_base raise CraftValidationError(f"Unknown base {base!r}") from err craft_application.errors.CraftValidationError: Unknown base 'core22-desktop' ``` ``` ### Additional context _No response_