x=one x="two and three" x=four x="five" x=-I/this x=-I"This or that" x=-Ithat x="-DTHIS=\"this and that\"" cfl=-I/this -I"This or that" -Ithat "-DTHIS=\"this and that\"" a=one b="two and three" a=four b="five" a=ONE b="TWO AND THREE" a=FOUR b="FIVE" We expect an error next: make: "forloop.mk" line 38: Wrong number of words (9) in .for substitution list with 2 vars make: Fatal errors encountered -- cannot continue make: stopped in unit-tests OK exit status 0