make: "cond-token-number.mk" line 16: Malformed conditional (-0) make: "cond-token-number.mk" line 27: Malformed conditional (+0) make: "cond-token-number.mk" line 38: Malformed conditional (!-1) make: "cond-token-number.mk" line 49: Malformed conditional (!+1) make: Fatal errors encountered -- cannot continue make: stopped in unit-tests exit status 1