make: "cond-undef-lint.mk" line 23: Variable "UNDEF" is undefined make: "cond-undef-lint.mk" line 38: Variable "UNDEF" is undefined make: "cond-undef-lint.mk" line 38: Variable "VAR." is undefined make: "cond-undef-lint.mk" line 49: Variable "VAR.defined" is undefined make: Fatal errors encountered -- cannot continue make: stopped in unit-tests exit status 1