make: varmod-gmtime.mk:60: Invalid time value "-1"
	while evaluating "${:L:gmtime=-1} != """ with value ""
make: varmod-gmtime.mk:70: Invalid time value " 1"
	while evaluating "${:L:gmtime= 1} != """ with value ""
make: varmod-gmtime.mk:117: Invalid time value "10000000000000000000000000000000"
	while evaluating "${:L:gmtime=10000000000000000000000000000000} != """ with value ""
make: varmod-gmtime.mk:129: Invalid time value "error"
	while evaluating "${:L:gmtime=error} != """ with value ""
make: varmod-gmtime.mk:139: Invalid time value "100000S,1970,bad,"
	while evaluating variable "%Y" with value "%Y"
make: Fatal errors encountered -- cannot continue
make: stopped making "all" in unit-tests
exit status 1