Fix:

/bin/sh: liblabltk.a: command not found

Part of:

https://github.com/garrigue/labltk/commit/befd8fc15f5f10efd693f99122132ab8b25feff3
--- support/Makefile.common.orig
+++ support/Makefile.common
@@ -35,3 +35,6 @@ LINKFLAGS=
 CAMLOPTLIBR=$(CAMLOPT) -a
 MKLIB=$(BINDIR)/ocamlmklib
 CAMLRUNGEN=$(BINDIR)/ocamlrun
+ifeq (x$(RANLIB),x)
+RANLIB=":"
+endif