cmd/go: how to use `go mod download` to download a module from http port 80 ?

[m3ng9i]

What version of Go are you using (go version)?

$ go version
go version go1.12.4 linux/amd64

Does this issue reproduce with the latest release?

Yes

What did you do?

I want to use go mod download command to download a private repository which is served at http port 80 (but not https port 443). The go mod download return an error:

    go: my-package.local/mypkg@v0.1.0: unrecognized import path "my-package.local/mypkg" (https fetch: Get https://my-package.local/mypkg?go-get=1: dial tcp <IP>:443: connect: connection refused)
    go: error loading module requirements

[ianlancetaylor]

CC @bcmills

Perhaps go mod download needs a -insecure flag.

[bcmills]

See #27332 (comment).

[bcmills]

Duplicate of #27332