> Look in bsd.port.mk.  Why specify the same location in every Makefile?

Since I don't run freebsd, I didn't have bsd.port.mk handy.  Having just
picked up a copy and read it, and having learned where ftp.freebsd.org keeps
what sure-enough appears to be a complete set of archival tar files, I have
to apologize for my earlier remark.  The storage mechanism isn't transparently
obvious, but given the assumed software base (a FreeBSD installation) it
adequately answers my complaint about invalidated references.