1make: cond-op-and.mk:36: Variable "UNDEF" is undefined 2make: cond-op-and.mk:41: Variable "UNDEF" is undefined 3make: cond-op-and.mk:44: Variable "UNDEF" is undefined 4make: cond-op-and.mk:60: Unknown operator '&' 5make: cond-op-and.mk:66: Unknown operator '&' 6make: cond-op-and.mk:72: Unknown operator '&' 7make: cond-op-and.mk:78: Unknown operator '&' 8make: cond-op-and.mk:87: Unknown operator '&' 9make: Fatal errors encountered -- cannot continue 10make: stopped in unit-tests 11exit status 1 12