Pango update fails - *** Must have at least one backend to build Pango.

[Lowell Gilbert]

> checking which cairo font backends could be used... none
> configure: Disabling cairo support
> configure: error: *** Could not enable any backends.

This is telling you that the cairo port, when you built it, did not
include any "font backends" (other ports for it to use in providing
fonts). You need to rebuild cairo first, making sure that you do a "make
config" on it to select a backend.