+export LD_LIBRARY_PATH:=$(if $(LD_LIBRARY_PATH),$(LD_LIBRARY_PATH):)$(STAGING_DIR_HOST)/lib
+export DYLD_LIBRARY_PATH:=$(if $(DYLD_LIBRARY_PATH),$(DYLD_LIBRARY_PATH):)$(STAGING_DIR_HOST)/lib
+
+# prevent perforce from messing with the patch utility
+unexport P4PORT P4USER P4CONFIG P4CLIENT
+
+# prevent user defaults for quilt from interfering
+unexport QUILT_PATCHES QUILT_PATCH_OPTS
+
+unexport C_INCLUDE_PATH