dpkg: man-db debconf error

Heute habe ich fehler auf einem Kunden System gehabt, das das Debian Paket man-db nicht richtig installiert werden konnte.
# apt-get install -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
After this operation, 0 B of additional disk space will be used.
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/DbDriver/File.pm line 44, chunk 3.
Use of uninitialized value in -e at /usr/share/perl5/Debconf/DbDriver/File.pm line 46, chunk 3.
Use of uninitialized value in pattern match (m//) at /usr/share/perl5/Debconf/DbDriver/File.pm line 47, chunk 3.
Use of uninitialized value $directory in -d at /usr/share/perl5/Debconf/DbDriver/File.pm line 48, chunk 3.
Use of uninitialized value $directory in concatenation (.) or string at /usr/share/perl5/Debconf/DbDriver/File.pm line 49, chunk 3.
debconf: DbDriver "config": mkdir :No such file or directory
Setting up man-db (2.6.2-1) ...
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/DbDriver/File.pm line 44, chunk 3.
Use of uninitialized value in -e at /usr/share/perl5/Debconf/DbDriver/File.pm line 46, chunk 3.
Use of uninitialized value in pattern match (m//) at /usr/share/perl5/Debconf/DbDriver/File.pm line 47, chunk 3.
Use of uninitialized value $directory in -d at /usr/share/perl5/Debconf/DbDriver/File.pm line 48, chunk 3.
Use of uninitialized value $directory in concatenation (.) or string at /usr/share/perl5/Debconf/DbDriver/File.pm line 49, chunk 3.
debconf: DbDriver "config": mkdir :No such file or directory
dpkg: error processing man-db (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
man-db
E: Sub-process /usr/bin/dpkg returned an error code (1)

Schnell war gefunden das der debconf Ortner fehlte:
mkdir /var/cache/debconf
apt-get install -f