This patch assumes that the installation tree is <prefix>/usr/bin
which is usually the case.

--- quilt-0.48/bin/quilt.in.org	2010-09-28 12:58:21.136446572 -0700
+++ quilt-0.48/bin/quilt.in	2010-09-28 13:16:36.984446032 -0700
@@ -14,7 +14,7 @@ export QUILT_DIR QUILT_LIB
 
 if [ -z "$QUILTRC" ]
 then
-	for QUILTRC in $HOME/.quiltrc /etc/quilt.quiltrc; do
+	for QUILTRC in $HOME/.quiltrc $QUILT_DIR/../../../etc/quilt.quiltrc; do
 		[ -e $QUILTRC ] && break
 	done
 	export QUILTRC