replication grpc.Client: panic: assignment to entry in nil map

[andres-erbsen]

I would guess this is a shutdown race, either in replication, replication test, or grpc-go.

panic: assignment to entry in nil map

goroutine 1085 [running]:
google.golang.org/grpc/transport.(*http2Client).NewStream(0xc820dce620, 0x31c0efc03a8, 0xc82000e6e0, 0xc8247f7c60, 0x0, 0x0, 0x0)
    /home/uhu/go/src/google.golang.org/grpc/transport/http2_client.go:270 +0x8c7
google.golang.org/grpc.sendRequest(0x31c0efc03a8, 0xc82000e6e0, 0x31c15039f08, 0xd57028, 0xc8247f7c60, 0x31c0df3d298, 0xc820dce620, 0x9f3dc0, 0xc820f22900, 0xc821020350, ...)
    /home/uhu/go/src/google.golang.org/grpc/call.go:73 +0x9c
google.golang.org/grpc.Invoke(0x31c0efc03a8, 0xc82000e6e0, 0xaa3450, 0x10, 0x9f3dc0, 0xc820f22900, 0x9f4ae0, 0xd57028, 0xc820e28840, 0x0, ...)
    /home/uhu/go/src/google.golang.org/grpc/call.go:169 +0x86f
github.com/yahoo/coname/server/replication/raftlog/proto.(*raftClient).Step(0xc82002e138, 0x31c0efc03a8, 0xc82000e6e0, 0xc820f22900, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
    /home/uhu/go/src/github.com/yahoo/coname/server/replication/raftlog/proto/raftrpc.pb.go:53 +0xec