cmd/go: go get -u golang.org/x/lint/golint fails in module mode

[ainar-g]

$ mkdir /tmp/foo && cd /tmp/foo
$ echo 'package foo // import "foo"' > main.go
$ go mod -init
$ go get -u golang.org/x/lint/golint
go get golang.org/x/lint/golint: missing module for import: golang.org/x/[email protected] provides golang.org/x/lint/golint

When I first saw this message, I thought it complained about the fact that I didn't import golang.org/x/lint/golint anywhere in my code. A better error message for such cases would be something like

golang.org/x/lint/golint is a part of golang.org/x/lint module; use go get golang.org/x/[email protected]

Or, even better, if the go tool knows the module I am trying to add, why not just add it?

[bcmills]

if the go tool knows the module I am trying to add, why not just add it?

That is intended to work as of https://golang.org/cl/122396. The fact that it doesn't is #25917, and I think this issue is a duplicate of that one. (Please reopen if it is not.)

[llimllib]

Another example that led me here, and which I'll leave here in case it helps somebody google or test:

$ go get golang.org/x/tools/cmd/goimports
go: finding golang.org/x/tools/cmd/goimports latest
go: finding golang.org/x/tools/cmd latest
go: finding golang.org/x/tools latest
go: downloading golang.org/x/tools v0.0.0-20180803180156-3c07937fe18c
go get golang.org/x/tools/cmd/goimports: missing module for import: golang.org/x/[email protected] provides golang.org/x/tools/cmd/goimports

[bcmills]

Thanks. I'm pretty sure this is another symptom of the root cause described in #26602 (comment).

[thepudds]

Seen in #modules, and possibly related to this issue:

$ go get github.com/Azure/azure-sdk-for-go/arm/compute@bd73d950fa4440dae889bd9917bff7cef539f86e
go: finding github.com/Azure/azure-sdk-for-go/arm/compute bd73d950fa4440dae889bd9917bff7cef539f86e
go: finding github.com/Azure/azure-sdk-for-go/arm/compute latest
go: finding github.com/Azure/azure-sdk-for-go/arm latest
go get github.com/Azure/azure-sdk-for-go/arm/compute@bd73d950fa4440dae889bd9917bff7cef539f86e: cannot find module providing package github.com/Azure/azure-sdk-for-go/arm/compute

go 11 beta 3
git version 2.18.0.windows.1
the code of interest exists at https://github.com/Azure/azure-sdk-for-go/tree/bd73d950fa4440dae889bd9917bff7cef539f86e
where the code of interest of interest is present in the azure sdk at that commit but not the latest version of the azure sdk

CC @myitcv

[myitcv]

@thepudds as discussed on Slack, that scenario is also a symptom of #26602 (comment); just confirmed that it's fixed by https://go-review.googlesource.com/c/go/+/128136

[bcmills]

Yep, I think at this point we can be pretty confident this is a dup of #26602.