def build_string(self):
        """
        Taskcluster denotes builds in one of two formats - i.e. linux64-asan or linux64-asan-opt
        The latter is generated. If it fails, the caller should try the former.
        """
        return (('-ccov' if self.coverage else '') +
                ('-fuzzing' if self.fuzzing else '') +
                ('-asan' if self.asan else '') +
                ('-valgrind' if self.valgrind else '') +
                ('-debug' if self.debug else '-opt'))
Taskcluster denotes builds in one of two formats - i.e. linux64-asan or linux64-asan-opt
        The latter is generated. If it fails, the caller should try the former.