[Rivet] rivet on mac osx lion

[Hendrik Hoeth]

Thus spake Hannes Jung (hannes.jung at cern.ch):

> even with disabling the pdfmanual, the problem remains (... the python issue).

Oh well, it seems the html manual is built anyway ... Try make install
nevertheless. You'll see the same error, but the manual is built as last
step, so the rest of the installation should succeed. The try if Rivet
runs. Good luck!

-- 
Man is the best computer we can put aboard a spacecraft, and
the only one that can be mass produced with unskilled labor.
                                        -- Wernher von Braun