Comment 20 for bug 1820291

Hi,

just wanted to add: This bug also crashes unattended-upgrade and thus prevents security updates on 18.04:

root@mailin1:~# unattended-upgrade
Traceback (most recent call last):
  File "/usr/bin/unattended-upgrade", line 1998, in <module>
    sys.exit(main(options))
  File "/usr/bin/unattended-upgrade", line 1714, in main
    if conffile_prompt(item.destfile):
  File "/usr/bin/unattended-upgrade", line 929, in conffile_prompt
    with open(prefix + conf_file, 'rb') as fp:
IsADirectoryError: [Errno 21] Is a directory: '/etc/qemu/fsfreeze-hook'

Basically, unattended-upgrade wants to compare old/new conffiles and doesn't like it when the old conffile turns out to be a directory...

This prevents security updates to be installed. The unattended-upgrade logs do not contain the trace, only the messages:

2019-04-05 13:24:24,851 INFO Initial blacklisted packages:
2019-04-05 13:24:24,853 INFO Initial whitelisted packages:
2019-04-05 13:24:24,853 INFO Starting unattended upgrades script
2019-04-05 13:24:24,854 INFO Allowed origins are: o=Ubuntu,a=bionic, o=Ubuntu,a=bionic-security, o=UbuntuESM,a=bionic'

And that's it.

You can't really get out of this without manually running 'apt-get install qemu-guest-agent' because at this point, unattended-upgrade can't update itself anymore.