[SciPy-user] Re: SciPy and I do not like libg2c-pic.a in Mandrake's gcc-2.96 and 3.xx

[Pearu Peterson]

On Mon, 27 May 2002, Gwenole Beauchesne wrote:

> Hi,
> 
> > When installing SciPy - a suite of scientific extensions for Python,
> > see www.scipy.org - I ran into a problem that I finally traced to
> > the requirement of having to link in libg2c-pic.a for dynamically loadable
> > libraries.
> 
> Any DSO must have PIC code. libg2c.a does not contain PIC code. Thus
> introducing libg2c-pic.a before libg2c was finally made shared in gcc3.1.  
> You haven't realized that problem yet probably because you were lucky
> enough under Linux/x86. This is not true everywhere.

I have added hooks to scipy_distutils to check if g2c-pic is available
(it was not too difficult) and use it instead of g2c if available. 
And indeed, also on debian gcc 2.95.4 and 3.0.x have g2c-pic library but
not in gcc 3.1.
Here follows a relevant fragment of the gcc changelog in debian woody:

gcc-2.95 (2.95.4.ds4-0.010826) unstable; urgency=low

  * Build libg2c.a with -fPIC -DPIC and name the result libg2c-pic.a.
    Link with this library to avoid linking with non-pic code.
    Use this library when building dynamically loadable objects (python
    modules, gimp plugins, ...), which need to be linked against g2c or
    a library which is linked against g2c (i.e. lapack). Packages needing
    '-lg2c-pic' must have a build dependency on
    'g77-2.95 (>= 1:2.95.4-0.010826).

 -- Matthias Klose <doko at debian.org>  Sun, 26 Aug 2001 13:59:03 +0200

Regards,
	Pearu