Impossible de faire la moindre mise à jour à cause d'une corruption du cache debconf

Ce qui rend impossible l'installation de paquet nécessitant debconf pour se configurer. Bloquant par la même occasion apt-get, vu qu'il réessaye à chaque nouvelle tentative de mise à jour de la distribution de réinstaller les paquets ayant échoués précédemment.

root@obelix:/var/log # apt-get -f install                                                                                                                    
Reading package lists... Done
Building dependency tree... Done
Correcting dependencies...Done
The following extra packages will be installed:
  xserver-xorg         
Suggested packages:    
  libglide2            
Recommended packages:  
  discover xresprobe   
The following NEW packages will be installed                                                                             
  xserver-xorg                                                                                                           
0 upgraded, 1 newly installed, 0 to remove and 78 not upgraded.                        
176 not fully installed or removed.                                                                                      
Need to get 0B/5732kB of archives.                                                                                       
After unpacking 16.2MB of additional disk space will be used.                                                            
Do you want to continue [Y/n]?                                                         
Preconfiguring packages ...                                                                                              
xserver-xorg config warning: Migrating xserver-xfree86 debconf values to                                                 
   xserver-xorg.                                                                                                         
Can't call method "choices" on an undefined value at /usr/share/perl5/Debconf/Question.pm line 106, <GEN1> line 118.
                                                                                                                                                                        
Received signal.  Aborting xserver-xorg package config script.
                                                                                                                                                                        
(Reading database ... 160475 files and directories currently installed.)
Unpacking xserver-xorg (from .../xserver-xorg_6.8.2.dfsg.1-11_i386.deb) ...
xserver-xorg config warning: Migrating xserver-xfree86 debconf values to
   xserver-xorg.                                                                                                                                                        
Can't call method "choices" on an undefined value at /usr/share/perl5/Debconf/Question.pm line 106, <GEN1> line 118.
dpkg: error processing /var/cache/apt/archives/xserver-xorg_6.8.2.dfsg.1-11_i386.deb (--unpack):
 subprocess pre-installation script returned error exit status 9
                                                            
Received signal.  Aborting xserver-xorg package config script.
                                        
Errors were encountered while processing:                                                
 /var/cache/apt/archives/xserver-xorg_6.8.2.dfsg.1-11_i386.deb                                                                                                          
E: Sub-process /usr/bin/dpkg returned an error code (1)             
root@obelix:/var/log #

Remise à zéro de l'ensemble des fichiers .dat présents dans /var/cache/debconf

Nous avons donc besoin de nettoyer les fichiers de cache de debconf pour repartir sur des bases saines.

root@obelix:/var/cache/debconf # for i in *dat
for> do cp $i $i.1
for> echo -n > $i
for> done                                                                            
root@obelix:/var/cache/debconf #

Refonctionnement optimale de apt-get

root@obelix:/var/cache/debconf # apt-get update
root@obelix:/var/cache/debconf # apt-get upgrade