I'm wondering how conditionals work with NetBSD Makefiles.  I need something 
like:

.if ${PERL_LEVEL} > 500600
IGNORE=         "This module is already included in Perl 5.6.x and later."
.endif

Which is code from FreeBSD port which ignores the module if Perl > 5.006 is 
installed (this is for module p5-IO, which became Perl core module in 
5.00307, but the newest version of the module is probably included with 
5.006), but this breaks on NetBSD.  What is done differently in NetBSD?
        Thanks, Roman Kulik