1
 2MAKEVER:=$(shell make --version | grep "Make [0-9]" | sed -E 's/.*Make ([0-9]).*/\1/')
 3
 4ifeq ($(MAKEVER),4)
 5
 6# GNU make 4 escapes $(SHELL).
 7test:
 8	echo test skipped
 9
10else
11
12export FOO=-x
13
14override SHELL := PS4="cmd: " /bin/bash $${FOO}
15$(info $(shell echo foo))
16
17test:
18	@echo baz
19
20endif