Comment 1 for bug 862383

Traceback (most recent call last):
  File "facetareabug.py", line 17, in <module>
    A2 = assemble(a2)
  File "/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/dolfin/fem/assembling.py", line 180, in assemble
    add_values)
  File "/opt/fenics/dorsal-unstable/lib/python2.7/site-packages/dolfin/cpp.py", line 19792, in assemble
    return _cpp.assemble(*args)
RuntimeError:

*** -------------------------------------------------------------------------
*** DOLFIN encountered an error. If you are not able to resolve this issue
*** using the information listed below, you can ask for help at
***
*** https://answers.launchpad.net/dolfin
***
*** Remember to include the error message listed below and, if possible,
*** include a *minimal* running example to reproduce the error.
***
*** -------------------------------------------------------------------------
*** Error: Unable to evaluate FacetArea expression.
*** Reason: Facet area is only defined on mesh boundaries.
*** Where: This error was encountered inside SpecialFunctions.cpp.
*** -------------------------------------------------------------------------