$(STAMP_DIR)/build target in debian/rules should depend on $(STAMP_DIR)/setup, not phony setup. One line fix attached.
diff -Nru debian.orig/rules debian/rules --- debian.orig/rules 2005-07-22 11:41:05.000000000 +0800 +++ debian/rules 2005-07-26 15:34:38.000000000 +0800 @@ -285,7 +285,7 @@ # DO NOT CHANGE THIS RULE WITHOUT CHECKING FOR SYNCHRONICITY WITH THE build-server RULE BELOW real-build: $(STAMP_DIR)/build -$(STAMP_DIR)/build: setup $(STAMP_DIR)/genscripts +$(STAMP_DIR)/build: $(STAMP_DIR)/setup $(STAMP_DIR)/genscripts # build Debian's X server wrapper $(CC) -Wall -g -O2 -o debian/local/xserver-wrapper debian/local/xserver-wrapper.c # Generate plain text documents from (X)HTML.