cmd/vet: line numbers don't show up for "internal package not allowed" errors from _test files

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

$ go version
go version go1.13.4 

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

darwin/amd64

go env Output

$ go env

What did you do?

1. Set the env variable in .zshrc:

export GOPATH=$HOME/Github/service

2. Open my test file:

// $HOME/Github/service/src/github.com/myName/project/internal/user/user_test.go
package user_test

import (
    ...
    "github.com/myName/project/internal/platform/web"
)

...

3. It report a suspicious state from go-vet checker, the warm message is:

imports github.com/myName/project/internal/platform/web:
use of internal package github.com/myName/project/internal/platform/web not allowed

[cagedmantis]

Hi @YUANLAI. I've attempted to reproduce the scenario posted above. go vet did not return any errors in my sample scenario. Can you post what command you are running that is producing these results?

I using emacs flycheck wrap the go-vet, the error occurs seems happen between flycheck and go-vet. flycheck/flycheck#1659 (comment)

[agnivade]

If the error comes from flycheck and not go-vet, then I'm afraid there is nothing we can do here.

But the issue you linked to shows that the issue is with vet. Could you please clarify ?

Please post the exact instructions that we can run from the command line to reproduce this. Thank you.

[nicks]

I think there are two bugs here (one in flycheck and one in the go tool) and they stack in weird ways.

The go tool bug is that when it finds a bad "internal package" use in a test file, it doesn't report line numbers properly.

For example:

$ go vet /tmp/scratch/podmonitor.go
/tmp/scratch/podmonitor.go:11:2: use of internal package github.com/windmilleng/tilt/internal/k8s not allowed
$ go vet /tmp/scratch/podmonitor_test.go 
package command-line-arguments (test)
	imports github.com/windmilleng/tilt/internal/container: use of internal package github.com/windmilleng/tilt/internal/container not allowed

Notice that the first invocation reports line numbers, and the second invocation does not.

This confuses flycheck, because flycheck's Go mode expects all Go error messages to have line numbers attached.

How hard is it to fix this error message to have the right line numbers?

[cpitclaudel]

To be clear, Flycheck is failing because go-vet is producing error messages that don't match the usual pattern (which includes a line number). Fixing that is just a matter of making that message conform to the usual template.

Now, the reason users are running into this message is that we create a temporary copy of their file (including unsaved changes) in a temporary directory before running go-vet; this breaks imports.

The ideal solution for us would be a way to feed file contents to go vet on stdin; then we wouldn't have to create temporary files: we'd just pass unsaved file contents on stdin and tell go-vet what the original file name was, so it could look up the imports properly. (this is what we're doing with most other checkers).

[agnivade]

Thanks for the clarification ! I have a few follow-up questions:

• Is this a regression or was it always there ?
• Is "use of internal package not allowed" the only error that does not have line number or are there other errors too ?