How to depends on perl conditionally?

[Lev Serebryakov]

Hello ports,

  If I use OPTIONS, I can check WITH_<option> only after `.include <bsd.port.pre.mk>'. But USE_PERL5 should be defined BEFORE this include too.
  What should I do if my port use perl, depending on options?! I can check WITH_PERL only AFTER include and I need to set USE_PERL5 before include :(


-- 
Best regards,
 Lev                          mailto:lev at FreeBSD.org