zonesigner no longer signs zones after 12.04 -> 14.0.4 upgrade

[Andrew]

After an upgrade from 12.04 to 14.04 zonesigner won't resign a zone:

root@foxtrot:/etc/bind# zonesigner -zone example.com example.com.zone
UNIVERSAL->import is deprecated and will be removed in a future perl at /usr/share/perl5/Net/DNS/SEC/Tools/tooloptions.pm line 19.

        if zonesigner appears hung, strike keys until the program completes
        (see the "Entropy" section in the man page for details)

root@foxtrot:/etc/bind#

lsb_release -rd
Description: Ubuntu 14.04 LTS
Release: 14.04

apt-cache policy dnssec-tools
dnssec-tools:
  Installed: 2.0-1
  Candidate: 2.0-1
  Version table:
 *** 2.0-1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe i386 Packages
        100 /var/lib/dpkg/status

[Andrew (sloof)]

If I create a new zone and sign it, zonesigner completes successfully.