Patch from Berhnard Fischer to keep duplicate objects out of the library.
diff --git a/archival/libunarchive/Makefile.in b/archival/libunarchive/Makefile.in
index 6ac9629..8bbcfdf 100644
--- a/archival/libunarchive/Makefile.in
+++ b/archival/libunarchive/Makefile.in
@@ -76,6 +76,7 @@
 
 libraries-y+=$(LIBUNARCHIVE_DIR)$(LIBUNARCHIVE_AR)
 
+LIBUNARCHIVE-y:=$(sort $(LIBUNARCHIVE-y))
 $(LIBUNARCHIVE_DIR)$(LIBUNARCHIVE_AR): $(patsubst %,$(LIBUNARCHIVE_DIR)%, $(LIBUNARCHIVE-y))
 	$(AR) $(ARFLAGS) $@ $(patsubst %,$(LIBUNARCHIVE_DIR)%, $(LIBUNARCHIVE-y))