MacPorts 4.6 on Lion - dependency libiconv not found?

I'm running OS X 10.7.3 and have successfully installed xtool 4.6 and the command line utilities for it. I have a local repository established, yet when I run this command: sudo ports install xdotool, the port is found, but I see this:

sudo port install xdotool

---> Computing dependencies for xdotool

Error: Dependency 'libiconv' not found.

Error: Status 1 encountered during processing.

yet when I look in /usr/lib, I see this:

ls -l /usr/lib/libiconv*

lrwxr-xr-x 1 root wheel 16 Feb 21 2012 /usr/lib/libiconv.2.4.0.dylib -> libiconv.2.dylib

-r-xr-xr-x 1 root wheel 2105216 Feb 21 2012 /usr/lib/libiconv.2.dylib

lrwxr-xr-x 1 root wheel 20 Feb 21 2012 /usr/lib/libiconv.dylib -> libiconv.2.4.0.dylib

I've seen posts that people have broken terminal and other packages by removing and reinstalling libiconv. What is the correct way to resolve the missing dependency, without breaking other installed packages?

Thanks.