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