hack makefile to fix coqchk invocation

Makefile

 # Makefile originally taken from coq-club
+
+%: Makefile.coq
+	+make -f Makefile.coq $@
+
 all: Makefile.coq
 	+make -f Makefile.coq all
 
@@ -6,10 +10,11 @@ clean: Makefile.coq
 	+make -f Makefile.coq clean
 	rm -f Makefile.coq
 
-Makefile.coq: _CoqProject
-	coq_makefile -f _CoqProject -o Makefile.coq
+Makefile.coq: _CoqProject Makefile
+	coq_makefile -f _CoqProject | sed 's/$$(COQCHK) $$(COQCHKFLAGS) $$(COQLIBS)/$$(COQCHK) $$(COQCHKFLAGS) $$(subst -Q,-R,$$(COQLIBS))/' > Makefile.coq
 
-%: Makefile.coq
-	+make -f Makefile.coq $@
+_CoqProject: ;
+
+Makefile: ;
 
 .PHONY: all clean