/go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1184 +0x10a4
  github.com/cockroachdb/cockroach/pkg/util/stop.(*Stopper).RunTaskWithErr()
      /go/src/github.com/cockroachdb/cockroach/pkg/util/stop/stopper.go:324 +0x129
  github.com/cockroachdb/cockroach/pkg/rpc.(*Context).runHeartbeat()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1150 +0x62c
  github.com/cockroachdb/cockroach/pkg/rpc.(*Context).grpcDialNodeInternal.func1.1()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1069 +0x94
  github.com/cockroachdb/cockroach/pkg/util/stop.(*Stopper).RunAsyncTaskEx.func2()
      /go/src/github.com/cockroachdb/cockroach/pkg/util/stop/stopper.go:442 +0x161

Previous write at 0x00c000577260 by goroutine 114:
  google.golang.org/grpc/internal/transport.(*http2Client).operateHeaders()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/internal/transport/http2_client.go:1295 +0x2309
  google.golang.org/grpc/internal/transport.(*http2Client).reader()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/internal/transport/http2_client.go:1484 +0xdb1

Goroutine 39 (running) created at:
  github.com/cockroachdb/cockroach/pkg/util/stop.(*Stopper).RunAsyncTaskEx()
      /go/src/github.com/cockroachdb/cockroach/pkg/util/stop/stopper.go:434 +0x28d
  github.com/cockroachdb/cockroach/pkg/util/stop.(*Stopper).RunAsyncTask()
      /go/src/github.com/cockroachdb/cockroach/pkg/util/stop/stopper.go:334 +0x494
  github.com/cockroachdb/cockroach/pkg/rpc.(*Context).grpcDialNodeInternal.func1()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1067 +0x3c1
  sync.(*Once).doSlow()
      /usr/local/go/src/sync/once.go:68 +0x109
  sync.(*Once).Do()
      /usr/local/go/src/sync/once.go:59 +0x68
  github.com/cockroachdb/cockroach/pkg/rpc.(*Context).grpcDialNodeInternal()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1061 +0x25c
  github.com/cockroachdb/cockroach/pkg/rpc.(*Context).GRPCDialNode()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context.go:1026 +0x88
  github.com/cockroachdb/cockroach/pkg/rpc.TestTestingKnobs()
      /go/src/github.com/cockroachdb/cockroach/pkg/rpc/context_test.go:1700 +0xa2c
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1193 +0x202

Goroutine 114 (running) created at:
  google.golang.org/grpc/internal/transport.newHTTP2Client()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/internal/transport/http2_client.go:346 +0x1488
  google.golang.org/grpc/internal/transport.NewClientTransport()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/internal/transport/transport.go:574 +0x6c7
  google.golang.org/grpc.(*addrConn).createTransport()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/clientconn.go:1328 +0x4f7
  google.golang.org/grpc.(*addrConn).tryAllAddrs()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/clientconn.go:1258 +0x507
  google.golang.org/grpc.(*addrConn).resetTransport()
      /go/src/github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc/clientconn.go:1173 +0x33b
==================
    testing.go:1092: race detected during execution of test
--- FAIL: TestTestingKnobs (0.11s)