My macports install got pretty messed up recently due to the way that perl5 (5.8, 5.10 and 5.12) is installed. It seem's that the default installation installs 5.8 which is old and conflicts with packages such as ikiwiki etc...

Pro-tip,

sudo port perl5 +perl5_12

Then install the apps that you want to use, but before doing so, do a

port variants PKG

before installing it, and install perl5 early on so that other packages that depend on it won't automatically pick perl 5.8.