Can't save pdfs with MPL devel under Jaunty

It must be me being stupid build MPL under the latest Ubuntu (has it
become harder lately? I have this impression), but I can't save pdfs with
a development version of MPL:

/home/varoquau/dev/matplotlib/lib/matplotlib/backends/ in
     42 from matplotlib.transforms import Affine2D, Bbox, BboxBase,
     43 from matplotlib.path import Path
---> 44 from matplotlib import ttconv
     46 # Overview

ImportError: /home/varoquau/dev/matplotlib/lib/matplotlib/
undefined symbol: _ZN14TTStreamWriter7putcharEi

Does anybody know what I am doing wrong?