program test_petsc38
#include <petsc/finclude/petscksp.h>
      use petscksp
      implicit none
!#include <petsc/finclude/petsc.h>
      KSP :: ksp
      Mat :: Amat
      Vec :: b,x
      PetscErrorCode :: ierr
      PetscInt :: i,ii(1), npetscloc,low,high, ione=1,izero=0,nreal
      PetscScalar :: ionearr(1)=1
      PetscInt, allocatable :: d_nnz(:), o_nnz(:)
      PetscViewer :: viewer
      integer :: comm

      !!!!misc initialization
      call PetscInitialize('./petsc.rc',ierr)
      !call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
      comm = PETSC_COMM_WORLD
      
      !!!!create Amat
      call MatCreate(comm,Amat,ierr)
      call MatSetType(Amat,MATAIJ,ierr)
      !instead of trying to recreate Amat, read in directly from previous XGC
      call PetscViewerBinaryOpen(comm,'Amat.dat',FILE_MODE_READ,viewer,ierr)
      call MatLoad(Amat,viewer,ierr)
      call PetscViewerDestroy(viewer,ierr)

      !!!!setup ksp
      call KSPCreate(comm,ksp,ierr)
      call KSPSetFromOptions(ksp,ierr)
      !call KSPSetOperators(ksp,Amat,Amat,SAME_NONZERO_PATTERN,ierr)
      call KSPSetOperators(ksp,Amat,Amat,ierr)
      ! setup solver now that matrix is complete
      !!!!!!!!NOTE: This is the call where an error is thrown
      call KSPSetUp(ksp,ierr)
      print *,'KSPSetUp finished'
      !!!!solve
!      call KSPSolve(ksp,b,x)

      call PetscFinalize(ierr)
end program test_petsc38