Comment 7 for bug 1856038

I tried to install on arm64 with subiquity 1415 (which includes curtin commit b022ed42), but it still fails:

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Processing triggers for flash-kernel (3.98ubuntu8) ...
dpkg: error processing package flash-kernel (--configure):
 installed flash-kernel package post-installation script subprocess returned error exit status 2
Errors were encountered while processing:
 flash-kernel
E: Sub-process /usr/bin/dpkg returned an error code (1)
Running command ['udevadm', 'settle'] with allowed return codes [0] (capture=False)
TIMED subp(['udevadm', 'settle']): 0.139
Running command ['umount', '/target/sys'] with allowed return codes [0] (capture=False)
Running command ['umount', '/target/proc'] with allowed return codes [0] (capture=False)
Running command ['umount', '/target/dev'] with allowed return codes [0] (capture=False)
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks/installing-kernel: FAIL: installing kernel
finish: cmd-install/stage-curthooks/builtin/cmd-curthooks: FAIL: curtin command curthooks
Traceback (most recent call last):
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/commands/main.py", line 202, in main
    ret = args.func(args)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/commands/curthooks.py", line 1592, in curthooks
    builtin_curthooks(cfg, target, state)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/commands/curthooks.py", line 1443, in builtin_curthooks
    install_kernel(cfg, target)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/commands/curthooks.py", line 369, in install_kernel
    distro.install_packages([kernel_package], target=target)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/distro.py", line 375, in install_packages
    env=env, allow_daemons=allow_daemons)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/distro.py", line 274, in run_apt_command
    return inchroot.subp(cmd, env=env)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/util.py", line 697, in subp
    return subp(*args, **kwargs)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/util.py", line 275, in subp
    return _subp(*args, **kwargs)
  File "/snap/subiquity/1415/lib/python3.6/site-packages/curtin/util.py", line 141, in _subp
    cmd=args)
curtin.util.ProcessExecutionError: Unexpected error while running command.
Command: ['unshare', '--fork', '--pid', '--', 'chroot', '/target', 'eatmydata', 'apt-get', '--quiet', '--assume-yes', '--option=Dpkg::options::=--force-unsafe-io', '--option=Dpkg::Options::=--force-confold', 'install', 'linux-generic']
Exit code: 100
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The full installer logs are attached.