Setting default package versions with MacPorts

Given a working Perl 5.12 install (via MacPorts), doing a sudo port install perl5.16 does not update the perl symlink:

% ls -alF /opt/local/bin/perl
lrwxr-xr-x 1 root admin 8 Jun 6 15:19 /opt/local/bin/perl@ -> perl5.12

The magic incantation is to install a the perl5_16 variant of the perl5 package:

sudo port install perl5 +perl5_16

With this done, the symlink is updated and perl loads the expected version.

% ls -alF /opt/local/bin/perl                                                                                                    
lrwxr-xr-x  1 root  admin  8 Aug  9 12:45 /opt/local/bin/perl@ -> perl5.16
% perl -v
This is perl 5, version 16, subversion 0 (v5.16.0) built for darwin-thread-multi-2level