Comment 1 for bug 91399

I have a similar error (up-to-date Kubuntu Feisty):
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stdin@home:~$ sudo dpkg --configure -a
Setting up console-setup (1.13ubuntu8) ...
dpkg: error processing console-setup (--configure):
 subprocess post-installation script returned error exit status 20
dpkg: dependency problems prevent configuration of ubuntu-minimal:
 ubuntu-minimal depends on console-setup; however:
  Package console-setup is not configured yet.
dpkg: error processing ubuntu-minimal (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 console-setup
 ubuntu-minimal
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After changing 'set -e' to 'set -ex' to the postinst I got:
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stdin@home:~$ sudo dpkg --configure -a
Setting up console-setup (1.13ubuntu8) ...
+ which md5sum
+ local IFS
+ IFS=:
+ [ -x /usr/local/sbin/md5sum ]
+ [ -x /usr/local/bin/md5sum ]
+ [ -x /usr/sbin/md5sum ]
+ [ -x /usr/bin/md5sum ]
+ echo /usr/bin/md5sum
+ return 0
+ md5sum=/usr/bin/md5sum
+ [ -z /usr/bin/md5sum ]
+ [ -f /usr/share/console-setup-mini/console-setup.config ]
+ CONFIGDIR=/etc/console-setup
+ CONFIGFILE=/etc/default/console-setup
+ . /usr/share/debconf/confmodule
+ [ ! ]
+ PERL_DL_NONLAZY=1
+ export PERL_DL_NONLAZY
+ [ ]
+ exec /usr/share/debconf/frontend /var/lib/dpkg/info/console-setup.postinst configure 1.13ubuntu7
dpkg: error processing console-setup (--configure):
 subprocess post-installation script returned error exit status 20
dpkg: dependency problems prevent configuration of ubuntu-minimal:
 ubuntu-minimal depends on console-setup; however:
  Package console-setup is not configured yet.
dpkg: error processing ubuntu-minimal (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 console-setup
 ubuntu-minimal
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so It looks like "exec /usr/share/debconf/frontend /var/lib/dpkg/info/console-setup.postinst configure 1.13ubuntu7" fails with status 20 (in my case)