If you use an extension module that links with libpthread,
problems related to errno occur (this is because some of the
code will use the normal single threaded errno variable, and
code loaded after pthread uses (*__errno_location()).

These problems can be fixed by LD_PRELOADing libpthread or
by building thread support into python.  The second option
is easier for users, and also allows threaded python
programs to run out of the box on redhat systems.

I have only just started to see these problems while
developing pygtk and gnome-python packages (since GTK
recently became threaded).  If you intend to include
gnome-python with the GNOME distribution, this change will
be needed to make gnome-python usable.