Traceback (most recent call last):
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/install.py", line 652, in install
    for_install_path = "cp://" + await self.configure_apt(context=context)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquitycore/context.py", line 149, in decorated_async
    return await meth(self, **kw)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/install.py", line 187, in configure_apt
    configurer = await mirror.wait_config(fsc._info.name)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 349, in wait_config
    await self._promote_mirror()
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 328, in _promote_mirror
    await self.run_mirror_selection_or_fallback(self.context)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 275, in run_mirror_selection_or_fallback
    await self.find_and_elect_candidate_mirror(context=context)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 212, in find_and_elect_candidate_mirror
    await self.try_mirror_checking_once()
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 171, in try_mirror_checking_once
    await self.run_mirror_testing(output)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/controllers/mirror.py", line 342, in run_mirror_testing
    await configurer.apply_apt_config(self.context, final=False)
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/apt.py", line 148, in apply_apt_config
    self.configured_tree = await self.mounter.setup_overlay([self.source_path])
  File "/snap/hostname-desktop-bootstrap/6/bin/subiquity/subiquity/server/apt.py", line 130, in source_path
    self._source_path = self.source_handler.setup()
  File "/snap/hostname-desktop-bootstrap/6/lib/python3.10/site-packages/curtin/commands/extract.py", line 123, in setup
    raise ValueError(
ValueError: Failed to use fsimage: '///cdrom/casper/minimal.en.squashfs' doesn't exist or is invalid