#include <petsc/private/petscimpl.h>

int main(int argc, char **args)
{
  PetscErrorCode ierr;
  MPI_Comm       newcomm;
  ierr = PetscInitialize(&argc, &args, NULL, NULL);CHKERRQ(ierr);
  ierr = PetscCommDuplicate(PETSC_COMM_WORLD, &newcomm, NULL);CHKERRQ(ierr);
  { // debug
    PetscCommCounter *counter;
    PetscMPIInt      flg;
    ierr = MPI_Comm_get_attr(newcomm,Petsc_Counter_keyval,&counter,&flg);CHKERRQ(ierr);
    if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_CORRUPT,"Bad MPI communicator supplied?");
  }
  ierr = PetscCommDestroy(&newcomm);CHKERRQ(ierr);
  return PetscFinalize();
}