UGGrid combined with grid from file does not compile with Python

This issue appeared while testing python programs written for 2.7 with the current master branches.

Here is a minimal example triggering this error:

import dune.grid
  
unstructuredGrid = dune.grid.ugGrid( (dune.grid.reader.gmsh, "l-shape.msh"), dimgrid=2 )

minimalProgramLog.txt l-shape.msh