SyncTask.swift

func doTheThing() {
  
    // First let's at least try to fix up each thing
    // Has to be one-at-a-time
    let waitGroup = DispatchGroup()
    for missingID in self.missingIDs {
        waitGroup.enter()
        self.utility.tryToFixStuff(forItemID: missingID) {
            waitGroup.leave()
        }
        waitGroup.wait() // this optionally takes a timeout param
    }
  
    // Go on doing the rest of the thing
    // ...
  
}

I'm always worried like "What if tryToFixStuff never calls me back!?" – Not sure if that's rational.

What are the odds that it fails? If it's a network thing there should be a time out.