Short answer: key grinding till you find the path

Real answer: it depends how important that task or the eventual result are to me. If its not that big of a deal and I'm just doing an off task but I'd know it'd be a failure I'd probably move on to something else and skip that or find someone else that could accomplish it for me. If it was something I need or could learn from those mistakes and the value was there then short answer would still apply.