"could not import syscall/js" error message even though it builds and runs successfully

[coreyog]

package main

import (
	"syscall/js"
)

func main() {
	js.Global().Call("alert", "Hello World")
}

When built with GOOS=js GOARCH=wasm go build main.go using Go 1.11 this produces a WASM binary without error. However VSCode shows that there's an error:

could not import syscall/js (can't find import: "syscall/js")

I think this has to do with that namespace being experimental while wasm support stabilizes over the coming versions. I'm given very little details about the error.

As a result of the namespace not being found, intellisense also doesn't work.

I'm running VSCode 1.26.1 on Linux Mint 19 x64 with Go 1.11

[coreyog]

I reopened the project to investigate further and when I moused over the import with it's red squiggly line, I got this error:

build constraints exclude all Go files in /usr/local/go/src/syscall/js

I think the plugin doesn't use an altered GOOS and GOARCH when checking the code for errors.

I tried setting go.toolsEnvVars in the project settings but I'm still getting the could not import error on the import.

[coreyog]

In Output I see:

/home/corey/src/goprojects/src/wasm-hw>Finished running tool: /home/corey/src/goprojects/bin/golint

/home/corey/src/goprojects/src/wasm-hw>Finished running tool: /usr/local/go/bin/go build -i -o /tmp/go-code-check.198072839 wasm-hw
go build runtime/internal/atomic: mkdir /usr/local/go/pkg/js_wasm: permission denied
go build runtime/internal/sys: open /usr/local/go/pkg/js_wasm/runtime/internal/sys.a: no such file or directory
go build internal/race: mkdir /usr/local/go/pkg/js_wasm: permission denied
go build sync/atomic: mkdir /usr/local/go/pkg/js_wasm: permission denied
go build internal/cpu: open /usr/local/go/pkg/js_wasm/internal/cpu.a: no such file or directory

/home/corey/src/goprojects/src/wasm-hw>Finished running tool: /usr/local/go/bin/go vet ./...

I've set my go.toolsEnvVars as follows:

{
  "go.toolsEnvVars": {
    "GOOS": "js",
    "GOARCH": "wasm",
    "GOROOT": "/usr/local/go",
    "GOPATH": "/home/corey/src/goprojects"
  }
}

GoRoot and GoPath reflect what the normal env variables are. I'm still getting the could not import error. I'm not sure why it's trying to do things in my /usr/local/go folder or how to tell it to build those files in $GOPATH/pkg.

Adding write privileges to the $GOROOT/pkg folder not only feels like a bad move, but it also doesn't entirely fix the problem. The error goes away but there's no intellisense for anything under js.

[eternal-flame-AD]

Experiencing the same issue.

[ramya-rao-a]

Can you try adding the setting "go.installDependenciesWhenBuilding": false. See #1464 for another case where the build process had permission issues

[eternal-flame-AD]

Ramya Rao (@ramya-rao-a) Thanks, I followed your steps and the error is not coming out. However, there is still no IntelliSense for syscall/js package.

[ramya-rao-a]

• If there are any running process for gocode, close them
• Run gocode -s -debug in a terminal and try for intellisense in VS Code. Results from gocode will show up in the terminal.

If the results from gocode show zero candidates, then the issue is with gocode

[eternal-flame-AD]

It indeed said zero candidates. I guess that's an upstream issue then.

[ramya-rao-a]

Are you using modules?
Also, can you try again by setting GOOS=js GOARCH=wasm in your terminal before running gocode -s -debug. Remember to kill existing processes for gocode

And why is the GOPATH being set to /home/corey/src/goprojects? Shouldnt it be just /home/corey ?

[coreyog]

It should be /home/corey/src/goprojects. /home/corey/src also has other non-Go project folders that I don't want mixed in with go projects.

I'll try setting env variables like you suggest when I get a chance.

[ramya-rao-a]

• What do you get when you run Go: Current GOPATH ?
• Are you using the new modules feature in Go 1.11?

[eternal-flame-AD]

I tried setting env before starting gocode but it is still not spawning candidates :(