Don't ever do this (but it works).

exhaust_waitgroup_hack.go

package main

import (
	"fmt"
	"strings"
	"sync"
)

func main() {
	var waiter sync.WaitGroup
	waiter.Add(10)
	go exhaust(&waiter)
	waiter.Wait()

	fmt.Printf("Hackity-hack!!!")
}

// exhaust drains the counter of the provided *sync.WaitGroup to avoid a deadlock.
// <hack>
// 	It uses the reflection-based capability of the fmt package to observe the
// 	internal state of the provided sync.WaitGroup. Who says you can't access
// 	unexported fields?
// </hack>
func exhaust(waiter *sync.WaitGroup) {
	for {
		state := fmt.Sprintf("%#v", waiter)
		if strings.Contains(state, "counter:0") {
			break
		} else {
			waiter.Done()
		}
	}
}