make: "varmod-loop-delete.mk" line 20: Cannot delete variable "VAR" while it is used
	while evaluating "${:U:@VAR@@} rest of the value" with value ""
	while evaluating variable "VAR" with value "${:U:@VAR@@} rest of the value"
make: Fatal errors encountered -- cannot continue
make: stopped making "all" in unit-tests
exit status 1