[GRASS-dev] r.mregression.series not installing

Hi, I am trying to install the r.mregression.series addon, but I am getting the following error:

GRASS 7.1.svn (Test):~ > g.extension extension=r.mregression.series
Fetching <r.mregression.series> from GRASS GIS Addons repository (be
patient)…
Compiling…
ERROR: Can’t import statsmodels. Install scipy package.
make: *** [r.mregression.series.tmp.html] Error 1
ERROR: Compilation failed, sorry. Please check above error messages.

The scipy package is, however, installed (I am on Ubuntu 14.04, and the package is installed using the official repository).

Any idea?