重新启动Golang HTTP服务器

I'm trying to use rerun to relaunch a go http server when the source files change, but the restart always fails to launch.

Simple server

package main

import (
    "net/http"
    "fmt"
    "log"
    "html"
)

func main() {
    http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
    })

    log.Fatal(http.ListenAndServe(":8080", nil))
}

Command line output

$ rerun -p "**/*.{go,html}" go run my_server.go

16:49:24 [rerun] Rerun_test launched
16:49:26 [rerun] Watching . for **/*.{go,html} using Darwin adapter
16:50:17 [rerun] Change detected: 1 modified
16:50:17 [rerun] Sending signal TERM to 75688

16:50:17 [rerun] Rerun_test restarted
2014/07/15 16:50:17 listen tcp :8080: bind: address already in use
exit status 1

16:50:19 [rerun] Rerun_test Launch Failed

How can I get this working, or why can't the server bind to the port when it is relaunched?

Also, I am using OSX 10.9.