Add USE_LIBTOOL=yes and LTCONFIG_OVERRIDE=${WRKSRC}/ltconfig to the package Makefile as the quick way to bypass the package's own libtool. The package's own libtool is made by the ``ltconfig'' script at ``do-configure'' time. If USE_LIBTOOL and LTCONFIG_OVERRIDE are defined, the specified ltconfig is overridden, using the ``devel/libtool'' command instead of the package's own libtool. If the pkg already has an original ``libtool'' which we can replace with the pkgsrc/devel/libtool you may have to specify LIBTOOL_OVERRIDE to the package Makefile.