preseeding encfs security question fails

[Andrew Wason]

Attempting to preseed the encfs package security question in xenial fails.

$ sudo debconf-set-selections <<< "encfs encfs/security-information error"
warning: Unknown type error, skipping line 1

Also tried with "seen":

$ sudo debconf-set-selections <<< "encfs encfs/security-information seen"
error: Cannot find a question for encfs/security-information

After installing and manually selecting OK for the security question, "seen" is then accepted, "error" is still not:

$ sudo apt-get install encfs
$ sudo debconf-get-selections | grep encfs
encfs encfs/security-information error
$ sudo debconf-set-selections <<< "encfs encfs/security-information seen"
$ sudo debconf-set-selections <<< "encfs encfs/security-information error"
warning: Unknown type error, skipping line 1

$ lsb_release -rd
Description: Ubuntu 16.04.2 LTS
Release: 16.04
$ apt-cache policy encfs
encfs:
  Installed: 1.8.1-3
  Candidate: 1.8.1-3
  Version table:
 *** 1.8.1-3 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status

[Andrew Wason (rectalogic)]

In bionic, now fails with:

$ sudo debconf-set-selections <<< "encfs encfs/security-information seen"
error: Cannot find a question for encfs/security-information
$ sudo debconf-set-selections <<< "encfs encfs/security-information error"
warning: Unknown type error, skipping line 1