Can anyone reproduce? With the latest trunk my demo-mixed-poisson and demo-mixed-poisson dual stopped converging. With uBLAS I get the message below. I only get the expected solution with Epetra.
%run demo_mixed-poisson-dual.py
Solving linear variational problem.
UMFPACK problem related to call to numeric
*** Warning: UMFPACK reports that the matrix being solved is singular.
UMFPACK problem related to call to solve
*** Warning: UMFPACK reports that the matrix being solved is singular.