SOMEVARIABLE=
ANOTHERVARIABLE=
showing the value of SOMEVARIABLE inside this make rule:
(not set)
showing the value of ANOTHERVARIABLE inside this make rule:
(not set)

SOMEVARIABLE=somevalue
ANOTHERVARIABLE=anothervalue
showing the value of SOMEVARIABLE inside this make rule:
SOMEVARIABLE=aaa
showing the value of ANOTHERVARIABLE inside this make rule:
ANOTHERVARIABLE=anothervalue