icon path other than /usr/share/icons

[Philip Brown <phil bolthole com>]

Howdy,

I'm compiling a gtk-based set of libraries under /opt, rather than the
usual. Things are going fairly well, except that it seems to keep
looking for icons under /usr/share/icons

I've read assorted web pages, that seem to mention things like
pixmap_path,  GTK2_RC, and themes.
But none of the above seem to help.

as far as themes go, even things that arent particularly theme heavy,
such as the simple "gtk-demo" program, seems to try to load icons from
/usr/share/icons, according to truss.
But I cant figure out why.  I cant figure out where it is even loading
any theme information from.

Running 'strings' on the libs doesnt show anything helpful, nor does
any master config file seem to be accessed that is making this happen,
according to truss.

I've looked in things like

$prefix/etc/gtk-2.0/gdk-pixbuf.loaders
$prefix/share/themes/Default/gtk-2.0-key/gtkrc

which DO get accessed... but they do not mention /usr share/icons

How do I get the gtk/gdk libs to look for icons in the $prefix I
compiled the libs with?