make: "cond-op-and.mk" line 36: Malformed conditional (0 || (${DEF} && ${UNDEF})) make: "cond-op-and.mk" line 41: Malformed conditional (0 || (${UNDEF} && ${UNDEF})) make: "cond-op-and.mk" line 44: Malformed conditional (0 || (!${UNDEF} && ${UNDEF})) make: "cond-op-and.mk" line 60: Unknown operator '&' make: "cond-op-and.mk" line 66: Unknown operator '&' make: "cond-op-and.mk" line 72: Unknown operator '&' make: "cond-op-and.mk" line 78: Unknown operator '&' make: "cond-op-and.mk" line 87: Unknown operator '&' make: Fatal errors encountered -- cannot continue make: stopped in unit-tests exit status 1