Bug#369942: Purge fails

[Frank Hart]

Package: mdadm
Version: 2.4.1-3

aptitude purge mdadm:

The following packages will be REMOVED:
  mdadm{p} 
0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
Need to get 0B of archives. After unpacking 356kB will be freed.
Do you want to continue? [Y/n/?] 
Writing extended state information... Done
(Reading database ... 118972 files and directories currently installed.)
Removing mdadm ...
Stopping RAID devices: done.
Stopping RAID monitor daemon: mdadm --monitor.
Purging configuration files for mdadm ...
/usr/share/debconf/confmodule: 19: DEBIAN_HAS_FRONTEND: parameter not set
dpkg: error processing mdadm (--purge):
 subprocess post-removal script returned error exit status 2
Errors were encountered while processing:
 mdadm
E: Sub-process /usr/bin/dpkg returned an error code (1)
A package failed to install.  Trying to recover:

And there it stops.

-- 
Frank Hart