Right now, the best way to work with gopls in VSCode is to use Workspace Folders per module. For every go.mod file that you have, you should do "File" > "Add Folder to Workspace" and then add the module root.

Sure 👍, but are there any plans to implement a feature like this? I'm betting most editors have this issue, not just VSCode.

I am having a similar issue, and am currently using bingo right now since it does support this.

Our monorepo has a similar setup as the issue reporters, where we have several services with their own go.mods, and most of them import another local library that contains common code for setting up logs and such.

root/
  deployables/
    service1/
      go.mod
    service2/
      /go.mod
  lib/
    common/
      go.mod

My experience has been that gopls doesn't load the full repository, and then is unable to figure out where things are.

How can I explicitly specify the module root for a given project?

This depends on your editor - if you are using VSCode, this can be done via File -> Add Folder to Workspace.

@stamblerre thank you for quick reply. I understand and can work with the limitation of having one module per-hierarchy, but it does not appear to matter unless the root folder is the one that has .mod. My projects pull supporting files one step up and have go.mod in {workspaceFolder}/src subfolder. Usually, for things like running debug, I can set the root:

{
    "version": "0.2.0",
    "configurations": [

        {
            "name": "Launch",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${workspaceFolder}/src", // <- specify where Go code is located
            "args": []
        }
    ]
}

Is there a similar workaround for gopls?

Yes, for gopls to work correctly the root folder has to be the one that contains your go.mod file. I do not believe there is any such workaround for gopls, but we will ultimately try to resolve this bug to make this work more seamlessly.

If there is a code path you can point to I’d love to take a stab at restoring my normality.

We still have to make some decisions about if this is the responsibility of gopls or of the editor. More likely than not, we would start off by making this change in VSCode-Go rather than in gopls.

fwiw @stamblerre the scenario I mentioned above is handled by https://github.com/saibing/bingo.

I guess I did mention that in my original comment.

@sint: The way that bingo does this is technically a "hack" (see saibing/bingo@169f54c). The module root is not necessarily the directory of the current file. A better solution would be to search for all directories containing mod files and notify gopls about them, but we still haven't made a final decision on how we want to implement this.

I'm under vim+ale+gopls and facing the same problem.

And I can not go to references in the standard library, I'm not sure if this is the same problem.

Hi, I've filed a proposal (#45713) for a workspace mode and config file that could be used to support the same workspace across the go command and gopls. Feel free to provide feedback if the proposal helps (or doesn't)!

I don't how you guys figured this out, but adding workspace folder and go.mod file worked for me! 😄️🚀️🎉️❤️

Having multiple go modules in a single Workspace doesn't produce that old error anymore, but now I'm getting another error:

[Error - 11:37:33 AM] 2021/10/04 11:37:33 initial workspace load failed: found module "github.com/cloudposse/terraform-aws-ec2-bastion-server" twice in the workspace

And then it complains about that on any action. Auto completion, intellisense and etc doesn't work.

@dee-kryvenko Can you please check if you have the mentioned module twice in the workspace indeed? That won't work any way. And, ideally please file a separate issue with the details with how you configured your workspace (used go.work+go1.18 dev version, or used the experimental workspace module?) .

Thanks - that was indeed the case. Well, not exactly - my terraform modules has been packaged together with their Terratest (Go Modules), and after Terraform got all dependencies unpacked under .terraform folder - the internals there was causing gopls to fail like that. I would never thought of that if not your comment, thanks @hyangah - though the error message is confusing, it was pointing me to go.mod files that legitimately had this module as a transitive dependency. It would have been helpful instead if it pointed me to all the locations the duplicated module actually declared at - not used as a dependency.

It now works like a charm.

Thanks for the great changes you've made. ❤️

Not sure if this is this ticket or a vs-code one needs to be opened, but this capability is doing something very weird to my go.mod, instead of listing the dependencies to keeps on reverting to (even after a go mod tidy):

module gopls-workspace

go 1.12

require gopls-workspace v1.9999999.0-goplsworkspace

replace gopls-workspace => $PROJECT_LOCAL_PATH

replace $PROJECT_IMPORT  =>  $PROJECT_LOCAL_PATH

So first off, is this the standard behavior? Will gopls work if I told it to kindly stop doing this as I definitly don't want local paths in a go.mod file?

Now I get this, similar to what I was having before #32394 (comment):

[Error - 10:57:51 PM] 2021/11/01 22:57:51 imports fixes: AllImportsFixes: found module "main" twice in the workspace

Obviously I do have much more than one main package in my workspace and it is expected. I'm pretty sure it worked before the recent upgrade.

Even with the workaround to open every module as a separate root, the extension cannot find references across modules in a monorepo. I think this is another issue?

@StarpTech My understanding is that modules open as separate workspace roots remain separate and gopls presents how go command would handle them. If you need to make it explicit that they are related, try Go1.18's go.work or use the experimental workspace module for older Go version.

gopls@v0.8.0 supports multi-module workspaces via integration with go.work files. However, I will leave this issue open until Go 1.18 comes out.

Go 1.18 is out. Please try out using gopls@v0.8.1 with go.work as described at https://github.com/golang/tools/blob/master/gopls/doc/workspace.md#go-workspaces-go-118

Right now, this works best if you create the go.work file before starting gopls. We're working on improving this workflow.

I'm going to close this issue in favor of other open issues to improve our go.work support.