I am getting this warning in notebooks, where I import some third-party libraries.
For example, if I include following imports in notebook:
import (
"fmt"
"github.com/gonum/stat"
"github.com/gonum/stat/distuv"
)
The warning appears.

Golang version:
(base) ➜ ai-notebooks git:(master) go version
go version go1.14.1 darwin/amd64
MacOS version:
(base) ➜ ai-notebooks git:(master) sw_vers -productVersion
10.15.4
Gopath:
(base) ➜ ai-notebooks git:(master) echo $GOPATH
/Users/genertorg/go
Gophernotes bin:
(base) ➜ ai-notebooks git:(master) "$(go env GOPATH)"/bin/gophernotes
2020/04/28 21:50:47 Need a command line argument specifying the connection file.