Simple solution for using a WaitGroup with select{}

changroup.go

package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	// Create a wait group of any size
	wg := sync.WaitGroup{}
	waitCh := make(chan struct{})
	wg.Add(10)

	// In another go routine Wait for the wait group to finish.
	go func() {
		// Run some actions
		for i := 0; i < 10; i++ {
			go func() {
				defer wg.Done()
				fmt.Println("do some action")

				// Uncomment to show timeout.
				// time.Sleep(100 * time.Millisecond)
			}()
		}

		wg.Wait()
		close(waitCh)
	}()

	// Block until the wait group is done or we timeout.
	select {
	case <-waitCh:
		fmt.Println("WaitGroup finished!")
	case <-time.After(100 * time.Millisecond):
		fmt.Println("WaitGroup timed out..")
	}
}

On some versions of go (apparently?) you can't wait for a closed channel.
You should instead make a bool channel and do waitCh1 <- true
...apparently. Yeah this only cropped up in production its weird.

Nice and simple. Thank you
Go playground link: https://goplay.tools/snippet/VQI-w53V9TW

For anyone interested, here is the recommended solution

https://pkg.go.dev/golang.org/x/sync/errgroup#Group