I have a matrix copy routine in a module as follows:

      subroutine f_rmatrixCopy_1(fArr,tArr)
         real(8), allocatable :: fArr(:), tArr(:)
         tArr = fArr
      end subroutine f_rmatrixCopy_1

When I call with

      call f_rmatrixCopy_1(BVS,SAVBVS)

I get on the assignment line:

     forrtl: severe(170): Program Exception - stack overflow

Both BVS and SAVBVS are allocated and are the same size (259081)

However when I replace the assignment with:

         do i = 1, size(farr)
           tArr(i) = fArr(i)
         enddo

All works fine.  Why doesn't the assignment work?