1err = $(error Error found)
 2
 3ifdef ERROR1
 4$(error error is $(ERROR1))
 5endif
 6
 7ifdef ERROR2
 8$(error error is $(ERROR2))
 9endif
10
11ifdef ERROR3
12all: some; @echo $(error error is $(ERROR3))
13endif
14
15ifdef ERROR4
16all: some; @echo error is $(ERROR4)
17	@echo $(error error is $(ERROR4))
18endif
19
20some: ; @echo Some stuff
21
22testvar: ; @: $(err)