orphaned port?

[Michelle]

I am trying to upgrade mysql-server and when I ran the make command, I 
received the following error:
===>  Installing for libtool-1.3.5_1
===>   Generating temporary packing list
===>  Checking if devel/libtool13 already installed
*** Error code 1

Stop in /usr/ports/devel/libtool13.
*** Error code 1

Stop in /usr/ports/databases/mysql323-server.

Than I ran pkg_version -v and saw the the libtool13 port is orphaned.  
What does this mean and how can I fix it?

Thank you,
Michelle