1
 2MAKEVER:=$(shell make --version | grep "Make [0-9]" | sed -E 's/.*Make ([0-9]).*/\1/')
 3
 4all: a.h.x a.c.x a.h.z a.c.z b.h.x b.c.x b.h.z b.c.z
 5
 6a.h.%:
 7	echo twice $@
 8a.c.%:
 9	echo twice $@
10
11b.h.% b.c.%:
12	echo once $@
13
14b.h.z: pass
15
16# GNU make 4 invokes this rule.
17ifeq ($(MAKEVER,3))
18b.c.z: fail
19endif
20
21pass:
22	echo PASS
23
24fail:
25	echo FAIL