pkgsrc picking up wrong fontconfig

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

I'm getting a failure configuring librsvg:

configure: error: Package requirements (        cairo >= 1.15.12 
       cairo-png >= 1.15.12            freetype2 >= 20.0.14 
gdk-pixbuf-2.0 >= 2.20  gio-2.0 >= 2.24.0                       glib-2.0 
>= 2.48.0              libxml-2.0 >= 2.9.0             pangocairo >= 
1.38.0            pangoft2 >= 1.38.0                    libcroco-0.6 >= 
0.6.1) were not met:

Package dependency requirement 'fontconfig >= 2.11.91' could not be 
satisfied.
Package 'fontconfig' has version '2.11.1', required version is '>= 2.11.91'

This is the version in /usr/X11R7/lib/pkgconfig/fontconfig.pc

However pkgsrc has built and installed fontconfig 2.13.1 so I don't know 
why its not picking up that version by default.

Mike