x/tools/gopls: importing wrong package "golang.org/x/exp/slices"

[jgardona]

I don't know exactly if this is an issue of gopls, but I think its good to post it here.
When using slices package, the lsp will always import the wrong go package
"golang.org/x/exp/slices", instead of the correct package "slices".

gopls version

Build info
----------
golang.org/x/tools/gopls v0.13.2
    golang.org/x/tools/[email protected] h1:Pyvx6MKvatbX3zzZmdGiFRfQZl0ohPlt2sFxO/5j6Ro=
    github.com/BurntSushi/[email protected] h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak=
    github.com/google/[email protected] h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
    github.com/sergi/[email protected] h1:we8PVUC3FE2uYfodKH/nBHMSetSfHDR6scGdBi+erh0=
    golang.org/x/[email protected] h1:+WEEuIdZHnUeJJmEUjyYC2gfUMj69yZXw17EnHg/otA=
    golang.org/x/exp/[email protected] h1:2O2DON6y3XMJiQRAS1UWU+54aec2uopH3x7MAiqGW6Y=
    golang.org/x/[email protected] h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
    golang.org/x/[email protected] h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
    golang.org/x/[email protected] h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
    golang.org/x/[email protected] h1:LAntKIrcmeSKERyiOh0XMV39LXS8IE9UL2yP7+f5ij4=
    golang.org/x/[email protected] h1:Oush7UwPamr2/iNeNFBuNFj89YyHn0YY69EKDdvANnk=
    golang.org/x/[email protected] h1:A9kONVi4+AnuOr1dopsibH6hLi1Huy54cbeJxnq4vmU=
    honnef.co/go/[email protected] h1:6qXr+R5w+ktL5UkwEbPp+fEvfyoMPche6GkOpGHZcLc=
    mvdan.cc/[email protected] h1:JVf4NN1mIpHogBj7ABpgOyZc65/UUOkKQFkoURsz4MM=
    mvdan.cc/xurls/[email protected] h1:tzxjVAj+wSBmDcF6zBB7/myTy3gX9xvi8Tyr28AuQgc=
go: go1.21.3

go env

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/jgardona/snap/alacritty/common/.cache/go-build'
GOENV='/home/jgardona/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/jgardona/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/jgardona/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/home/jgardona/Bin/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/jgardona/Bin/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.3'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build251818100=/tmp/go-build -gno-record-gcc-switches'

What did you do?

Use slices package and wait for the gopls autocomplete works

What did you expect to see?

Import "slices" package

What did you see instead?

It imports "golang.org/x/exp/slices" package

Editor and settings

• vscode info
  Version: 1.83.1
  Commit: f1b07bd25dfad64b0167beb15359ae573aecd2cc
  Date: 2023-10-10T23:45:31.402Z
  Electron: 25.8.4
  ElectronBuildId: 24154031
  Chromium: 114.0.5735.289
  Node.js: 18.15.0
  V8: 11.4.183.29-electron.0
  OS: Linux x64 6.5.0-9-generic snap

• no settings

[seankhliao]

what's in your go.mod?

[jgardona]

what's in your go.mod?

❯ cat ../../go/example/go.mod
module example

go 1.21.3

[danp]

@jgardona did you end up with exp/slices as part of a completion or as part of "organize imports" (possibly on save)?

In other words, was it from doing something like:

func main() {
  slic<> // cursor at <> and golang.org/x/exp/slices suggested
}

or:

package main

func main() {
	slices.Sort([]int{5, 4, 3}) // hit save after typing this and `import "golang.org/x/exp/slices"` appears above
}

[jgardona]

@danp Hello. Good afternoon.

Exactly. I typed "slices.", then hit enter and "golang.org/x/exp/slices" was imported.

[danp]

I see you're using golang.org/x/tools/gopls v0.13.2.

I believe the issue is that gopls embeds a list of stdlib packages and their exported symbols. That list is used by the completion bits to understand what stdlib packages are available. You can see the version of that list gopls v0.13.2 uses here (which, because gopls is its own module and requires tools, is dependent on what go.mod says here). There's no entry for the stdlib slices package since list was generated using info from Go 1.20 (as mentioned in the commit message).

To get a version of gopls that uses the more recent list generated from Go 1.21 (which does include slices) you'd need to try a gopls v0.14.0 prerelease, such as gopls/v0.14.0-pre.4.

You should be able to try it with the example go install command there. If you're unable to try it, I think you'll need to wait for a proper v0.14.0 release.

And hopefully someone from the gopls team will correct me if I've gotten something wrong!

[jgardona]

I'll wait gopls 0.14.0 and see what will be the output.

[hyangah]

gopls v0.14.0-pre.5 is available for testing. At least, it seems to work for me and suggests slices as the very first one. (the second one is the one in golang.org/x/exp/slices, but my project already depends on golang.org/x/exp). And file save imports "slices" automatically.

[findleyr]

gopls v0.14.0 is out now. @jgardona please let us know if this resolves your problem.

[jgardona]

gopls v0.14.0 is out now. @jgardona please let us know if this resolves your problem.

confirmed here it was fixed. Thank you all 🙂

[jgardona]

will close as it was fixed in 0.14