Haskell: how to catch fail

If something returns m Xyz in it calls fail inside it, then how to catch the fail? The way is to call it but with some concrete monad, for instance under Maybe or Either - depends on the monad's constraints: res::Maybe Int <- itReturnsMXyz and now you can determine where it's fail or successful result.

How to make alternatives for several m Xyz? Like m Xyz1 | m Xyz2 | m Xyz3?

Idea is the same: just force m to be some satisfied monad, for example, Maybe (if Maybe is OK for m's constraints:

catMaybes [fun x, fun y, fun z]

If fun x/y/z returns different types then convert them into the same one - to have homogeneous list:

catMaybes [X <$> fun x, X <$> fun y, X <$> fun z]

Now they all are of a type X; just an idea.