If an effect targets exhausted units, does it whiff if the unit becomes ready before the effect resolves?

Ruling: Effects that are restricted to exhausted units will whiff if that unit becomes ready before the effect resolves. A unit that is exhausted when an effect finalizes is no longer a legal target if it is not exhausted on resolution.

Nuances:

• This applies when a unit leaves the play-field and then comes back (it would no longer be exhausted)
• The unit must still meet the targeting restriction (being exhausted) at resolution, not just when initially targeted