I am trying to debug an application code that works with v3.7 but fails with master. The code works for "normal" solvers but for a solver that uses FieldSplit it fails. It looks like vectors are not getting created from MatCreateVecs with a matrix that is a MatNest (I can't run the code). I have put print statements in the interface files to try to see what is going on but the print statements seem to disappear somehow. (I added the same print statements in my installation of v3.7 to see what is different) I was using PetscPrint and then found and example of a Fortran PetscInfo and switched to that. I stepped through the code with DDT and see the print statements but nothing goes to the output. I did this DDT stuff with ex73f90t, which has a MatCreateNest. I am completely baffled. Does anyone have any ideas? Thanks, Mark