[ale] Problem using new libs to build gtk+

[John Mills]

ALErs -

I'm wandering the 'maze of twisty passages' to build gimp-2.4, and having 
trouble with 'gtk+-2.12.10'. I built it's prerequisite 'cairo-1.6.4', but 
when I run '[gtk+-2.12.10]/configure' it only recognizes older 'cairo' 
installations and fails to create 'Makefile' and sibs. All these 
GTK-related pieces (pango, cairo, gtk+, and ultimately gimp) are going 
into '/opt/gnome'.

How can I get 'gtk+' to configure with the newly built prerequisites?

TIA.

  - Mills