I had some problems giving a container an PETSc object so I wrapped it in a struct. I forget what problem I had. Maybe ISColoringDestroy can't take a void*. I'd like to check if I was just missing something. Should something like this work? ISColoring c; .... ierr = PetscContainerSetPointer(container,(void*)c);CHKERRQ(ierr); ierr = PetscContainerSetUserDestroy(container, ISColoringDestroy);CHKERRQ(ierr);