The following recipe worked on RH9 and gentoo 1.4: 1. Set environment variable USE_LAPACK: export USE_LAPACK=1 2. Edit addon.py and make the following changes: 1. Change the first item of lapack_libs from 'blas' to 'atlas' 2. Change lapack_dirs from [] to ['directory of libatlas.a', 'directory of libg2c.a'] 3. Proceed with the usual installation: python setup.py ... I had some problem on the RH9 system that were solved by upgrading to a recent ATLAS package. Enjoy ;) Nadav.