autotrust fails to deinstall

[Teun Vink]

Binary package hint: autotrust

purging autotrust fails:

# dpkg --purge autotrust
(Reading database ... 77947 files and directories currently installed.)
Removing autotrust ...
 * Stopping DNSSEC trust anchor updater autotrust [ OK ]
sh: getcwd() failed: No such file or directory
Purging configuration files for autotrust ...
sh: getcwd() failed: No such file or directory
userdel: unrecognized option '--system'
Usage: userdel [options] LOGIN

Options:
  -f, --force force removal of files,
                                even if not owned by user
  -h, --help display this help message and exit
  -r, --remove remove home directory and mail spool

dpkg: error processing autotrust (--purge):
 subprocess installed post-removal script returned error exit status 2

This is caused by the --system flags in /var/lib/dpkg/info/autotrust.postrm or userdel and groupdel, removing these flags fixes it.