Comment 8 for bug 1561467

I disagree with Martin, this is not about deconfigure being an unknown argument if it were we'd see the following in DpkgTerminalLog:

Preparing to unpack .../systemd_229-4ubuntu6_amd64.deb ...
De-configuring udev (225-1ubuntu9.1) ...
dpkg-maintscript-helper: error: command symlink_to_dir is unknown
Hint: upgrading dpkg to a newer version might help.

Use 'dpkg-maintscript-helper help' for program usage information.
dpkg: error processing archive /var/cache/apt/archives/systemd_229-4ubuntu6_amd64.deb (--unpack):
 subprocess installed pre-removal script returned error exit status 1

However, we are getting "exit status 2" which is bug 1606767.