Impossible d'installer ia32-libs dans Debian Wheezy

J'essayais d'installer ia32-libs dans Debian Wheezy. J'ai l'erreur

The following packages have unmet dependencies:
 ia32-libs : Depends: ia32-libs-i386 but it is not installable
E: Unable to correct problems, you have held broken packages.

j'utilise

# uname -a
Linux debian 3.2.0-4-amd64 #1 SMP Debian 3.2.41-2 x86_64 GNU/Linux

Mon sources.lst est

# cat /etc/apt/sources.list
# 

# deb cdrom:[Debian GNU/Linux 7.0.0 _Wheezy_ - Official amd64 DVD Binary-1 20130504-14:44]/ wheezy contrib main

# deb cdrom:[Debian GNU/Linux 7.0.0 _Wheezy_ - Official amd64 DVD Binary-1 20130504-14:44]/ wheezy contrib main

deb http://security.debian.org/ wheezy/updates main contrib
deb-src ftp://ftp.iitm.ac.in/debian/ wheezy/updates main contrib

# wheezy-updates, previously known as 'volatile'
# A network mirror was not selected during install.  The following entries
# are provided as examples, but you should amend them as appropriate
# for your mirror of choice.
#
deb http://ftp.debian.org/debian/ wheezy-updates main contrib
deb http://http.us.debian.org/debian/ wheezy contrib non-free main
# deb-src http://ftp.debian.org/debian/ wheezy-updates main contrib
deb http://ftp.us.debian.org/debian stable main contrib non-free
deb http://security.debian.org/ wheezy/updates main contrib non-free

Depuis Wheezy introduit multiarch, le ia32-libspackage est désormais obsolète. Il est désormais possible d'installer directement des packages 32 bits:

dpkg --add-architecture i386 # enable multi-arch
apt-get update
apt-get install libc6:i386 # install base 32bit libraries