use of closed network connection

[lookfirst]

Copied the code on the homepage, but now I print out the error from http.Serve().

./test
2019/06/06 15:42:07 [overseer master] run
2019/06/06 15:42:07 [overseer master] starting /tmp/main/test
2019/06/06 15:42:07 [overseer slave#1] run
2019/06/06 15:42:07 [overseer slave#1] start program
2019/06/06 15:42:07 app (f81a86c0d7a5120aa306900493dacb542143ca66) listening...
2019/06/06 15:42:45 [overseer master] graceful restart triggered
2019/06/06 15:42:45 [overseer slave#1] graceful shutdown requested
2019/06/06 15:42:45 accept tcp [::]:3000: use of closed network connection
2019/06/06 15:42:45 [overseer master] signaled, sockets ready
2019/06/06 15:42:45 [overseer master] starting /tmp/main/test
2019/06/06 15:42:45 [overseer master] restart success
2019/06/06 15:42:45 [overseer slave#2] run
2019/06/06 15:42:45 [overseer slave#2] start program
2019/06/06 15:42:45 app (f81a86c0d7a5120aa306900493dacb542143ca66) listening...

The problem is that when I do a kill -s SIGUSR2 PID, I sometimes get an error along the lines of:

accept tcp [::]:3000: use of closed network connection

Ideas?

[zltgo]

I have the same problem, also in fvbock/endless.
why?

[yrashk]

I also am running into this. Any discoveries on this end?