After upgrading Mac OS X to newest version Mavericks, I attempted to selfupdate my Macports, but it failed:
$ sudo port -v selfupdate ---> Updating MacPo
The problem seems to be with Macports and the location of the Tcl framework and it's path once Xcode has been installed. I suggest installing a fresh version of Macports for Mavericks here : http://www.macports.org/install.php.