[Pythonmac-SIG] SciPy install on Tiger with Python 2.4.1 framework

Bill Northcott w.northcott at unsw.edu.au
Fri Aug 12 11:01:15 CEST 2005

On 12/08/2005, at 4:26 AM, Brian Granger wrote:
> What version of gcc are you using?  I have not had any luck getting  
> scipy and its dependencies working with gcc 4.0.
> Maybe this has changed?  Has anyone had success with gcc 4.0 yet?
> If you need to change the default version of gcc on Mac OS X use  
> the command:
> sudo gcc_select 3.3

This is probably the solution.
because you can only use g77 with gcc-3.x OR gfortran with gcc-4.x.   
You cannot use g77 with gcc-4 they are incompatible.
So if you have a Python/R/Perl/you-name-it binary containing Fortran  
objects built with g77 you cannot extend it with code compiled with  
gcc-4.  This is true on any platform.

The issue arises mainly on Tiger because it does not have an included  
Fortran compiler and out of the box it defaults to using gcc-4.   
Binary packages are shipped built with g77 and sometimes including  
g77.  These are bound to fail on Tiger unless the default compiler is  
changed using the gcc_select command as above.

I have built Scipy with gcc-4, but you must use gfortran to compile  
all the Fortran code for that to work.

I do wish someone on Python, R-project or some other web site would  
document this issue.  I must have posted at least twenty messages  
saying the same thing.

Bill Northcott

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