Repairing a cracked wheel?

I take it that the wheel is a generic wheel that came on the car from the factory. Just buy a new one from a salvage yard. That's a no brainer.

For custom wheels that you can no longer find anywhere, both cast and forged aluminum can be fixed. There are several companies that offer the service. St. Mary's Tire, Charlies Rim Repair, Weldcraft (aren't taking new work right now), Rim Spec, Detroit Wheel & Tire. A proper repair takes some welding skill and machining afterwards. It's usually best to kerf cut the crack completely out and fill it with weld.