This patch is needed to build on Debian AMD64, where libraries are in "lib" rather that "lib64".

This was fixed in commit b3a5225f31180322fd7d692fd4cf786702826b94 that went into 2.6.15.

diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -155,6 +155,7 @@
 	fi; \
 	LIBPATH=$$DIR/lib; LIB=qt; \
 	$(HOSTCXX) -print-multi-os-directory > /dev/null 2>&1 && \
+	  test -d $$DIR/lib/$$($(HOSTCXX) -print-multi-os-directory) && \
 	  LIBPATH=$$DIR/lib/$$($(HOSTCXX) -print-multi-os-directory); \
 	if [ -f $$LIBPATH/libqt-mt.so ]; then LIB=qt-mt; fi; \
 	echo "QTDIR=$$DIR" > $@; echo "QTLIBPATH=$$LIBPATH" >> $@; \