==================
WARNING: DATA RACE
Write by goroutine 16:
  sync.raceWrite()
      /go/src/sync/race.go:41 +0x35
  sync.(*WaitGroup).Wait()
      /go/src/sync/waitgroup.go:125 +0x177
  net/http/httptest.(*Server).Close()
      /go/src/net/http/httptest/server.go:168 +0x83
  net/http_test.TestClientTimeout_Headers()
      /go/src/net/http/client_test.go:952 +0xb1a
  testing.tRunner()
      /go/src/testing/testing.go:454 +0xfb

Previous read by goroutine 22:
  sync.raceRead()
      /go/src/sync/race.go:37 +0x35
  sync.(*WaitGroup).Add()
      /go/src/sync/waitgroup.go:63 +0xc8
  net/http/httptest.(*waitGroupHandler).ServeHTTP()
      /go/src/net/http/httptest/server.go:198 +0x5f
  net/http.serverHandler.ServeHTTP()
      /go/src/net/http/server.go:1758 +0x209
  net/http.(*conn).serve()
      /go/src/net/http/server.go:1259 +0x1161

Goroutine 16 (running) created at:
  testing.RunTests()
      /go/src/testing/testing.go:562 +0xc95
  testing.(*M).Run()
      /go/src/testing/testing.go:492 +0xe7
  net/http_test.TestMain()
      /go/src/net/http/main_test.go:19 +0x35
  main.main()
      net/http/_test/_testmain.go:536 +0x20c

Goroutine 22 (running) created at:
  net/http.(*Server).Serve()
      /go/src/net/http/server.go:1806 +0x422
==================
PASS
Found 1 data race(s)
FAIL  net/http  43.465s