Ensure $(COMPAT_LEVEL) evaluated lazily

Author: dra27

Makefile

@@ -150,13 +150,13 @@ COMPILER-$(COMPAT_VERSION):
 test_ver = $(shell if [ $(COMPAT_VERSION) -ge $(1) ] ; then echo ge ; fi)
 
 # This list must be in order
-COMPAT_LEVEL := \
-  $(strip $(if $(call test_ver,40100),401) \
-          $(if $(call test_ver,40200),402) \
-          $(if $(call test_ver,40300),403) \
-          $(if $(call test_ver,40500),405) \
-          $(if $(call test_ver,40600),406) \
-          $(if $(call test_ver,40700),407))
+COMPAT_LEVEL = $(eval COMPAT_LEVEL := \
+  $$(strip $$(if $$(call test_ver,40100),401) \
+           $$(if $$(call test_ver,40200),402) \
+           $$(if $$(call test_ver,40300),403) \
+           $$(if $$(call test_ver,40500),405) \
+           $$(if $$(call test_ver,40600),406) \
+           $$(if $$(call test_ver,40700),407)))$(COMPAT_LEVEL)
 
 Compat.ml: Compat.ml.in COMPILER-$(COMPAT_VERSION)
 	sed -e '$(if $(COMPAT_LEVEL),/^$(subst $(SPACE),@\|^,$(COMPAT_LEVEL))@/d;)s/^[0-9]*@//' $< > $@