category() not backwards compatible

I just got:

/home/mblatt/src/dune/current/dune-pdelab/dune/pdelab/backend/istl/ovlpistlsolverbackend.hh:495:13: error: cannot declare variable ‘pop’ to be of abstract type ‘Dune::PDELab::OverlappingOperator<Dune::PDELab::ConstraintsTransformation<Dune::PDELab::DOFIndex<long unsigned int, 2ul, 2ul>, Dune::PDELab::MultiIndex<long unsigned int, 2ul>, double>, Dune::PDELab::ISTL::BCRSMatrix<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BCRSMatrix<Dune::FieldMatrix<double, 3, 3>, std::allocator<Dune::FieldMatrix<double, 3, 3> > >, Dune::PDELab::ISTL::PatternStatistics<long unsigned int> >, Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > >, Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > > >’
         POP pop(c,A);
             ^
/home/mblatt/src/dune/current/dune-pdelab/dune/pdelab/backend/istl/ovlpistlsolverbackend.hh:44:11: note:   because the following virtual functions are pure within ‘Dune::PDELab::OverlappingOperator<Dune::PDELab::ConstraintsTransformation<Dune::PDELab::DOFIndex<long unsigned int, 2ul, 2ul>, Dune::PDELab::MultiIndex<long unsigned int, 2ul>, double>, Dune::PDELab::ISTL::BCRSMatrix<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BCRSMatrix<Dune::FieldMatrix<double, 3, 3>, std::allocator<Dune::FieldMatrix<double, 3, 3> > >, Dune::PDELab::ISTL::PatternStatistics<long unsigned int> >, Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > >, Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > > >’:
     class OverlappingOperator
           ^
In file included from /home/mblatt/src/dune/current/dune-swf/src/dune_swf.cc:27:0:
/home/mblatt/src/dune/current/dune-istl/dune/istl/operators.hh:86:38: note: 	Dune::SolverCategory::Category Dune::LinearOperator<X, Y>::category() const [with X = Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > >; Y = Dune::PDELab::ISTL::BlockVector<Dune::PDELab::PowerGridFunctionSpace<Dune::PDELab::GridFunctionSpace<Dune::GridView<Dune::UGGridLeafGridViewTraits<const Dune::UGGrid<2> > >, Dune::PDELab::P0LocalFiniteElementMap<double, double, 2>, Dune::PDELab::P0ParallelConstraints, Dune::PDELab::ISTL::VectorBackend<> >, 3ul, Dune::PDELab::ISTL::VectorBackend<(Dune::PDELab::ISTL::Blocking)2, 3ul>, Dune::PDELab::EntityBlockedOrderingTag>, Dune::BlockVector<Dune::FieldVector<double, 3>, std::allocator<Dune::FieldVector<double, 3> > > >]
     virtual SolverCategory::Category category() const

with updated istl and pdelab.

Seems connected to pdelab/dune-pdelab!250 (merged)