How to replace a function

[tomas]

Hi, lists

we are trying to build a guile extension which should link
smoothly against 1.6 and 1.7. If possible, we would like
to use The Blessed Function (it's scm_c_string2str(), for
the record). But alas, 1.6 hasn't got that. It seems that
AC_REPLACE_FUNCS is the right macro (first do AC_CHECK_LIB,
right?).

The problem is that AC_REPLACE_FUNCS will find one version
of the Guile library, whereas the version I'm going to link
against is the one returned by `guile-config link' or whatever.

My question: Is there a canonical way to solve this? I.e.
is there a way to tell AC_REPLACE_FUNCS *which* library to
look into? Or is it just meant to cope with ``standard system
libraries'' and am I to re-invent the wheel and do a
tentative compile?

Thanks for any hints

-- tomas