Synonyms to labor of Sisyphus

labor in vain, be found wanting, be unsuccessful, beat the air, bootless errand, come to grief, fail, fail of success, flunk, flunk out, go bankrupt, lash the waves, lose, lost, milk the ram, not come off, not pass, not work, snipe hunt, sow the sand, tilt at windmills, waste of breath, waste of labor, waste of time, wild-goose chase, work of Penelope, wild goose chase, abortion, abortive attempt, dud, merry chase, miscarriage, miscarrying, misfire, vain attempt, wet squib