Run the the example fail

[figureout]

i run by copy exmaple code, it print nothing.
my go version:
go version go1.21.5 linux/amd64
than i change func Read sema.Add(1) to main goroutine inside the for block it run well

···code:
userCount := 10
for i := 0; i < userCount; i++ {
fmt.Printf("go init func: %d\n",i)
sema.Add(1) // move it to here
go iRead(i)
}

does it matter to go version