Hello - I've come up with the following test case to illustrate my problem: file empty.f: subroutine empty(arr, nx,ny ) implicit none integer, intent(in) :: nx,ny real, dimension(nx,ny), intent(out) :: arr print *, "in empty." arr = 1.0e0 end subroutine empty using the following to compile: f2py -c -m empty -lSystemStubs --opt=-O3 --fcompiler=ibm --f90exec=/ opt/ibmcmp/xlf/8.1/bin/xlf90 --f90flags=-O3 empty.f Builds empty.so just fine. Python 2.5.1 (r251:54869, Apr 18 2007, 22:08:04) [GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin

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from empty import empty as myempty from numpy import * # for illustration purposes. myempty(1,1) in empty. array([[ 1.]], dtype=float32)

But when I import numpy first, I get the following: Python 2.5.1 (r251:54869, Apr 18 2007, 22:08:04) [GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin

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from numpy import * from empty import empty as myempty myempty(1,1) Segmentation fault $

Platform: Mac OS X, 10.4.10, using ibm-xlfortran v. 8.1. $ f2py -v 2_3844