I have got my files from here: https://trac.macports.org/browser/trunk/dports/devel/subversion?rev=80777 - placed them under a similar folder tree, cd'ed into there and ran
gigi-kents-system-product-name:subversion 1.6.17 macport kellogs$ sudo port install Can't map the URL 'file://.' to a port description file ("Could not find Portfile in /Users/kellogs/subversion 1.6.17 macport "). Please verify that the directory and portfile syntax are correct. To use the current port, you must be in a port's directory.
I would have expected for the portfile's syntax to be correct actually.
What's up with that ?