Problem while install tetex

[Prakash Countcham <prakash.countcham@imag.fr>]

Hi,

I was confronted to a bug in the version of babel of Debian testing:

\def\useshorthands#1{%
  \def\user@group{user}%
  \initiate@active@char{#1}%
  \bbl@activate{#1}}

should be:

\def\useshorthands#1{%
  \def\user@group{user}%
  \initiate@active@char{#1}%
  \@tempcnta\lccode`\~
  \lccode`~=`#1%
  \lowercase{\catcode`~\active\bbl@activate{~}}%
  \lccode`\~\@tempcnta}

Instead of opening a bug that is corrected in the experimental version, I
tried to install this one:
# apt-get install -t experimental tetex-base tetex-bin tetex-doc tetex-extra

But unfortunately, dpkg fails with the following error:
/var/lib/dpkg/info/tetex-base.postinst: 429: update-language: not found

How could I install the experimental version ?

Thanks in advance for your help,

-- 
Prakash