[SciPy-user] Compiling extensions in a virtual environment

[Pierre GM]

All,
I'm trying to compile scikits.timeseries in a virtual environment  
(created w/ virtualenvwrapper), and I'm running into a puzzling problem.

When I create a new virtual environment, install numpy in it (from  
SVN, r6685), I'm able to compile the scikit without problem. However,  
after removing the build and switching to another existing virtual  
environment, I get a:
error: build/src.macosx-10.5-i386-2.5/gfortran_vs2003_hack.c: No such  
file or directory
Where does this error come from ? As the virtual environment that  
causes problem is the one that I work with all the time, I'd like to  
know what's happening.

Notes:
* Reinstalling numpy in this environment (after removing previous  
installation and the corresponding eggs) doesn't seem to fix the pb.
* Python 2.5.4 (r254:67916, Dec 29 2008, 17:02:44)
[GCC 4.0.1 (Apple Inc. build 5488)] on darwin

Thanks a lot in advance for any pointer.
P.