### Bug Description I am trying to cross-compile a kernel for a ARM64 device, and it seems on both 7.x/stable and 8.x/stable channels that the snapcraft application fails to download the snapd:arm64 package, with the error: E: Can't select candidate version from package snapd:arm64 as it has no candidate Failed to build 'kernel'. This build-process happens on a Ubuntu Focal Multipass instance running on a AMD64 machine. Snapcraft versions: 7.x/stable (7.5.8) and 8.x/stable (8.5.1) This has worked last time I tried to compile a kernel, a few months back. ### To Reproduce Not sure how to replicate, try to cross-compile a kernel? Multipass instance compile options: (Manual compile commands) `snapcraft --target-arch=arm64 --destructive-mode --enable-experimental-target-arch --enable-experimental-plugins` ### Environment Running Multipass snap, version 1.15.0 on Ubuntu Bionic machine Mutipass container version: Ubuntu 20.04.6 LTS ### snapcraft.yaml ```yaml name: my-kernel version: "20-8" adopt-info: kernel summary: Generic Linux kernel description: | Kernel for testing grade: stable confinement: strict type: kernel architectures: - build-on: amd64 run-on: arm64 build-base: core20 parts: kernel: plugin: kernel source: github-link-removed source-type: git source-branch: lf-5.10.y source-depth: 1 kernel-kdefconfig: [imx8_var_defconfig, snappy/generic.config, snappy/security.config, snappy/systemd.config, snappy/snappy.config, snappy/containers.config ] kernel-kconfigs: - CONFIG_LOCALVERSION="-v0.8" - CONFIG_SYSFS=y - CONFIG_GPIO_SYSFS=y - CONFIG_GPIO_GENERIC=y - CONFIG_HW_RANDOM_TPM=m - CONFIG_TCG_TPM=m - CONFIG_TCG_TIS_CORE=m - CONFIG_TCG_TIS_SPI=m - CONFIG_SECURITYFS=y - CONFIG_LSM="yama,integrity,apparmor" - CONFIG_SECURITY_APPARMOR=y - CONFIG_AUDIT=y - CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE=1 - CONFIG_DEFAULT_SECURITY_APPARMOR=y - CONFIG_SYN_COOKIES=y - CONFIG_STRICT_DEVMEM=y - CONFIG_DEBUG_RODATA=y - CONFIG_CC_STACKPROTECTOR=y - CONFIG_CC_STACKPROTECTOR_STRONG=y - CONFIG_DEBUG_SET_MODULE_RONX=n - CONFIG_ENCRYPTED_KEYS=y - CONFIG_SQUASHFS_XATTR=y - CONFIG_SQUASHFS_XZ=y - CONFIG_DEVPTS_MULTIPLE_INSTANCES=y - CONFIG_TMPFS_XATTR=y - CONFIG_TMPFS_POSIX_ACL=y override-pull: | snapcraftctl pull set -e echo "Applying Ubuntu Core AppArmor patches to the kernel..." git apply -v ../../../patches/apparmor-patch-510.patch git apply -v ../../../patches/configs-patch-510.patch snapcraftctl set-version "20-8" kernel-initrd-compression: lz4 kernel-initrd-firmware: - firmware/imx/sdma/sdma-imx7d.bin kernel-device-trees: [ freescale/imx8mp-device-tree-for-kernel ] kernel-image-target: Image kernel-with-firmware: false kernel-add-ppa: true kernel-initrd-stage-firmware: true organize: kernel.img: Image after: [ firmware ] build-packages: - cpio - libc6-dev - bison - flex - lzop - libssl-dev - on amd64 to arm64: - gcc-aarch64-linux-gnu:amd64 #TODO Strip most firmwares out to make kernel smaller. firmware: plugin: nil source: linux-firmware override-build: | mkdir -p $SNAPCRAFT_PART_INSTALL/firmware cp -av ../../../linux-firmware/* $SNAPCRAFT_PART_INSTALL/firmware/ build-packages: - zstd - bison - device-tree-compiler - dpkg-dev - flex - initramfs-tools-core - libfdt-dev - libssl-dev - lzop - python3-crypto - python3-pycryptodome - python3-pyelftools - python3-serial - u-boot-tools - wget - libjson-c-dev - binutils-${SNAPCRAFT_ARCH_TRIPLET} - gcc-${SNAPCRAFT_ARCH_TRIPLET} ``` ### Relevant log output ```shell + '[' -d /home/ubuntu/kernel/parts/kernel/src/kernel ']' + KERNEL_SRC=/home/ubuntu/kernel/parts/kernel/src + echo PATH=/snap/snapcraft/13058/libexec/snapcraft:/snap/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin PATH=/snap/snapcraft/13058/libexec/snapcraft:/snap/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin + echo KERNEL_SRC=/home/ubuntu/kernel/parts/kernel/src KERNEL_SRC=/home/ubuntu/kernel/parts/kernel/src + initrd_installed_kernel_modules= + initrd_configured_kernel_modules= + echo 'Getting ubuntu-core-initrd....' Getting ubuntu-core-initrd.... + '[' '!' -e /home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs ']' + download_core_initrd arm64 /home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs + apt-get download ubuntu-core-initramfs:arm64 Get:1 http://ppa.launchpad.net/snappy-dev/image/ubuntu focal/main arm64 ubuntu-core-initramfs arm64 51.15 [18.2 MB] Fetched 18.2 MB in 48s (381 kB/s) W: Download is performed unsandboxed as root as file '/home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs_51.15_arm64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) + dpkg -x ubuntu-core-initramfs_51.15_arm64.deb /home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs + echo 'Getting snapd deb for snap bootstrap...' Getting snapd deb for snap bootstrap... + '[' '!' -e /home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs/usr/lib/snapd ']' + download_snap_bootstrap arm64 /home/ubuntu/kernel/parts/kernel/build/ubuntu-core-initramfs + apt-get download snapd:arm64 E: Can't select candidate version from package snapd:arm64 as it has no candidate Failed to build 'kernel'. Recommended resolution: Check the build logs and ensure the part's configuration and sources are correct. ``` ### Additional context _No response_