Hello, I have just hit this today:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721583
Update:
It's fixed in debian's ruby-gettext 3.0.0-2 and in siduction's 3.0.0-2~pre1 available in fixes/. See: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721574
If you end up with a broken apt-listbugs you could do the following:
1. dpkg --remove apt-lustbugs
2. Dist upgrade your system.
3. As soon as you get one ruby-gettext version install apt-listbugs again.
Here you have the *.deb, in case you need it:
http://packages.siduction.org/fixes/pool/main/r/ruby-gettext/ruby-gettext_3.0.0-2~pre1_all.deb