What version of Go are you using (go version)?
go1.10.3
Does this issue reproduce with the latest release?
No
What did you do?
The race is between ServerMux.Handle and ServerMux.Handler, but it was fixed in 2fd1b52
I just want to be sure that it'll be backported to 1.10.4, because it makes continuous race detection hard and also race is fatal because it's between map read and write.