An older version of x11-fonts/libXft is already installed (Xft-2.1.2_1) You may wish to install this port again to upgrade it properly. Set the variable “FORCE_PKG_REGISTER” in your environment or the “make install” command line to install the new version via the port: X11.6. The new version of X11 is now being used to update the X11 version of libXft.”]
Source: https://taosecurity.blogspot.com/2004/04/fixing-problematic-port-while-trying.html