Emdebian Multistrap and wheezy-grip

Hello All,

Currently i am using Emdebian on a project and am happy using the
mutlistrap with the stable suite to build root file systems.

However I would like to experiment with the testing branch (wheezy).

I tried to add in my multistrap config file the suite as wheezy-grip but
multistrap fails with:
*    libtext-charwidth-perl : Depends: perlapi-5.12.3 but it is not
installable*
*
*
Is it possible to build Emdebian rootfs with mutlistrap for the testing
branch?

Cheers,
Adam