On Wed, Dec 23, 2009 at 4:40 AM, Pauli Virtanen <pav@iki.fi> wrote: > I suppose raising an exception requires ownership of GIL. I am curious: how did you know it was related to the GIL ? When I tried debugging the issue, I could not tell whereas this was a problem with python 2.7 or with numpy, and did not suspect the GIL at all. David