scipy for fedora extras & will GCC/gfortran updates happen for FC-4 ?

[Ed Hill]

On Wed, 2005-10-19 at 10:35 +0100, Morgan Hough wrote:
> I have checked the archives as best I can and I don't see any mention
> of this so here goes. SciPy is a great python numerical package which
> is also a dependency for many specialized scientific packages.
> Apparently there is a problem with gcc-4.0.1's fortran support and
> SciPy can't be built on an fc4 system (without third party commercial
> software). Here's a more complete description of the problem from the
> SciPy-users list:
> 
> <quote>
> In an all-default configuration, it is not presently possible to build a
> working scipy on Fedora Core 4, either old or new.  There is a bug in
> gfortran which causes it to mis-compile the i1mach, r1mach, and d1mach
> functions which are at the bottom of much of the Fortran code in scipy.
> If you use g77 instead by using the appropriate compatibility RPMs
> (compat-gcc-32-g77 and compat-libf2c-32), you'll find that gcc4 cannot
> link to libg2c because it isn't in a directory which gcc4 searches.  I
> haven't found a way of forcing a scipy build to use gcc 3.2.3 (the
> compatibility version which is part of FC4).
> 
> The only feasible workaround I've found is to use g77 on FC4 to build
> scipy (and Numeric and numarray), and create symbolic links to libg2c.a
> and libg2c.so so that gcc4 can find them.  That is, do the following:
> 
> ln -s /usr/lib/gcc-lib/i386-redhat-linux/3.2.3/libg2c.so
> /usr/lib/gcc/i386-redhat-linux/4.0.1
> ln -s /usr/lib/gcc-lib/i386-redhat-linux/3.2.3/libg2c.a
> /usr/lib/gcc/i386-redhat-linux/4.0.1
> 
> This is not supported, use at your own risk, your mileage may vary,
> results are not guaranteed, pressure RedHat to release a gcc 4.0.2
> update for FC4 in which the gfortran bug is fixed.  Personally, I'm
> using Absoft Fortran on gcc4;  if you're an educational institution,
> Intel will let you download and use their Fortran compiler for free.
> Both seem to work fine with newscipy and FC4.
> </quote>

Hi Morgan,

I've only tinkered with scipy a little but some of my coworkers use it
regularly and I help them with scipy installs.  I'd be happy to help you
create and maintain a scipy package for Fedora Extras since it is useful
for us.  Would you be interested?


> I was wondering what can be done about this as I for one know of many
> projects that build on SciPy. Is there any chance that 4.0.2 would be
> released as an update? Who would decide such a thing? Is there an
> acceptable Fedora Extras workaround that could be used instead? Thanks
> in advance for your time.

I'm certain that the above-mentioned soft links can be handled in a much
better/cleaner fashion within a scipy RPM spec file.

Also, I'm interested in hearing about GCC updates.  We use Fortran (g77
and gfortran) a lot so, like you, we're very interested in seeing the
recent GCC improvements and bugfixes shipped for FC-4.

So, who may we ask about possible GCC updates for FC-4?  Can anyone
point us in the right direction?

thanks,
Ed

-- 
Edward H. Hill III, PhD
office:  MIT Dept. of EAPS;  Rm 54-1424;  77 Massachusetts Ave.
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