Can I stop linking the same library twice?

[Ralf Wildenhues]

* Dr. David Kirkby wrote on Thu, Dec 31, 2009 at 02:44:50AM CET:
> Ralf Wildenhues wrote:
> >* Dr. David Kirkby wrote on Sat, Dec 12, 2009 at 12:08:11PM CET:
> >>I have seen issues in the Sage mathematics software
> >
> >>where problems arise if a library included in Sage is installed on
> >>the system too. Sage included the source for all the libraries it
> >>needs (e.g. readline), in case the system does not have that
> >>library. That sometimes causes problems, if the option "-L
> >>$SAGE_HOME/local/lib" is added and the library is also on the
> >>system.
> >
> >Is libtool used to create this library?  Then this shouldn't happen
> >(famous last words), and if it does, it's typically the sign of a bug in
> >the makefiles or in libtool somewhere.

> No, libtool is not used. Nor is autoconf or automake. Sage consists
> of about 100 open source packages. For each one, there is a small
> script which builds that package, which at the bare essentials might
> be:

That doesn't answer the question though.  Your super-project Sage might
not use libtool, nor might some of the packages it is comprised of.  If
the sub package where the failing link happens uses libtool though,
above advice might still apply.

> In other cases it might the script which does the building might be
> a python script. Each one is customised to build that particular bit
> of software.

I don't think you can debug them without going into specifics and
looking at each one that is failing.

Cheers,
Ralf