While trying to compile the darwinports base on MacOS X 10.3.4 Panther, I got this error when I ran the configure script:

checking for Tcl package directory... configure: error: Tcl package directory not found.  
Please specify its location with --with-tclpackagedir

This is the configure option that I used that makes it work:

./configure --with-tclpackagedir=/System/Library/Frameworks/Tcl.framework/Versions/8.4