www/p5-RT-Extension-MandatoryOnTransition does not recognize rt40 is installed

[Marko Cupać]

I am trying to compile www/p5-RT-Extension-MandatoryOnTransition but on
9.2-RELEASE i386 and perl5.18, but the port does not recognize that
rt4 is already installed:

===>   p5-RT-Extension-MandatoryOnTransition-0.04 depends on package: rt>4.0.8 - not found

Consequently it tries to install rt40 but fails as it is already installed:

===>  Checking if www/rt40 already installed
===>   rt40-4.0.18 is already installed
      You may wish to ``make deinstall'' and install this port again
      by ``make reinstall'' to upgrade it properly.
      If you really wish to overwrite the old port of www/rt40
      without deleting it first, set the variable "FORCE_PKG_REGISTER"
      in your environment or the "make install" command line.
*** [check-already-installed] Error code 1

How can I fix this?

-- 
Marko Cupać