Typically covered under warranty.
Especially if the failure was caused by some other piece of the motor, such as a seal or crack in something that wasn't supposed to have a crack in it.
BTW, how often would you consider a clutch to fail, typically, in terms of distance driven?
I've seen them last for 200K Miles before, with someone that knows how to properly use a clutch.
I've also seen clutches only last 300 Miles, because the person rode with thier foot on the pedal, causing slippage that cooked the clutch, glazing the clutch disk, the clutch pressure plate and the flywheel.