Given that we have not supported releases older than 8.3 for quite a
while, do we need to keep this in extend.sgml any longer?
<caution>
<para>
Changing <varname>PG_CONFIG</varname> only works when building
against <productname>PostgreSQL</productname> 8.3 or later.
With older releases it does not work to set it to anything except
<literal>pg_config</>; you must alter your <varname>PATH</>
to select the installation to build against.
</para>
</caution>
cheers
andrew