Accepted proposal: a goroutine leak profile in the Go standard library

Go 1.27 is getting a goroutine leak detector in runtime/pprof. The proposal was accepted in April. A few common goroutine leaks # A goroutine leaks when it blocks forever on a channel or a lock that nothing will ever release, so it lingers for the life of the process. I’ve been using uber-go/goleak to catch them in tests. One is an early return that strands a sender, which I covered in Early return and goroutine leak . It looks like this: func run(tasks []func() error) error { errs := make(chan error) // unbuffered var wg sync.WaitGroup for _, task := range tasks { wg.Go(func() { errs <- task() }) // (1) } for range tasks { if err := <-errs; err != nil { return err // (2) } } wg.Wait() return nil } Here: (1) each task sends its result on the unbuffered channel through wg.Go (2) the first error returns early, so the tasks still queued to send block forever Giving errs a buffer big enough for every task, or draining all the results before returning, keeps the sends from blocking. A…