RISC-V 22.40 installation fails: Unsupported arch

[Heinrich Schuchardt]

The installation of GRUB fails with 'Unsupported arch: riscv64'.

[Heinrich Schuchardt (xypron)]

$ snap info subiquity
installed: 22.07.2

[Heinrich Schuchardt (xypron)]

When using an SD card to reinstall on a system which by default boots into the existing installation the user can interrupt the boot process and boot via the U-Boot command line.

The problem occurs when booting the casper/vmlinuz via the legacy entry point and not via the EFI stub. How can we signal this early to the user?

Can we make force the installer to make an EFI installation of GRUB even if booting in legacy mode?

[Dan Bungert (dbungert)]

 finish: cmd-install/stage-curthooks/builtin/cmd-curthooks: FAIL: curtin command curthooks
 Traceback (most recent call last):
   File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/main.py", line 202, in main
     ret = args.func(args)
   File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/curthooks.py", line 1886, in curthooks
     builtin_curthooks(cfg, target, state)
   File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/curthooks.py", line 1851, in builtin_curthooks
     setup_grub(cfg, target, osfamily=osfamily,
   File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/curthooks.py", line 804, in setup_grub
     install_grub(instdevs, target, uefi=uefi_bootable, grubcfg=grubcfg)
   File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/install_grub.py", line 381, in install_grub grub_name, grub_target = get_grub_package_name(target_arch, uefi, rhel_ver) File "/snap/subiquity/3706/lib/python3.8/site-packages/curtin/commands/install_grub.py", line 82, in get_grub_package_name
     raise ValueError('Unsupported arch: %s' % target_arch)
 ValueError: Unsupported arch: riscv64
 Unsupported arch: riscv64
 curtin: Installation failed with exception: Unexpected error while running command.
 Command: ['curtin', 'curthooks']
 Exit code: 3