go mod download can't find module tag v0.0.1

[dwschulze]

$ go version
go1.15.1 linux/amd64

I have a module in github.

I added this to my ~/.gitconfig: [url "ssh://[email protected]/"] insteadOf = https://github.com/

When I try to use the module from my main go mod download cannot find v0.0.1 of the module even though the tag v0.0.1 exists in github:

$ go run main.go
go: github.com/dwschulze/[email protected]/go.mod: verifying module: github.com/dwschulze/[email protected]/go.mod: reading https://sum.golang.org/lookup/github.com/dwschulze/[email protected]: 410 Gone
        server response: not found: github.com/dwschulze/[email protected]: invalid version: unknown revision v0.0.1

$ go mod download  github.com/dwschulze/[email protected]
github.com/dwschulze/[email protected]/go.mod: verifying module: github.com/dwschulze/[email protected]/go.mod: reading https://sum.golang.org/lookup/github.com/dwschulze/[email protected]: 410 Gone
	server response: not found: github.com/dwschulze/[email protected]: invalid version: unknown revision v0.0.1

The tag v0.0.1 exists:

$ git clone [email protected]:dwschulze/go-module-test-dateutilmod.git
Cloning into 'go-module-test-dateutilmod'...
...
$ cd go-module-test-dateutilmod/
$ git tag
v0.0.1

[bcmills]

See go help module-private or https://golang.org/ref/mod#private-module-proxy-direct.

[bcmills]

That said, we should give a better error message for this.

[bcmills]

Duplicate of #25982

[dwschulze]

I was able to get this to work with export GOPRIVATE=githib.com. So I thought I understood what the problem was and what the solution was. But then if I delete GOPATH/pkg and do unset GOPRIVATE I found that it still works. It downloads the module into GOPATH/pkg:

$ echo $GOPRIVATE

$ go run main.go
go: downloading github.com/dwschulze/go-module-test-dateutilmod v0.0.1
github:  2020-09-18 18:21:58.244789426 -0600 MDT  //  output from main()

But it shouldn't work with GOPRIVATE unset. What is going on that it works? Is there a hidden cache somewhere?

[dwschulze]

I do not believe that this is a duplicate of #25982. That is an earlier version of go and the issue seems to be credentials for vcs repos, not what go mod download does.