x/tools/gopls: "method textDocument/completion did not reply"

[foxcpp]

What did you do?

1. Use gopls with LanguageClient-neovim.
2. Open the file with the following contents:

package main

import "net"

type S struct {
	F int
}

func main() {
	s := S{}

}

3. Place the cursor on the empty line in main and type s.F, a = net,
4. LanguageClient-neovim triggers completion to show net contents.

• The issue is not specific to the net package, but does not affect all packages. errors works correctly. net, os and github.com/wireguard/wgctrl-go do not.
• I do not know whether the issue is specific to the LanguageClient-neovim behavior or not.
• If the package is not imported and completeUnimported is enabled, completion is shown correctly.

What did you expect to see?

Completion popup with things exported by net .

What did you see instead?

gopls exits, no completion is shown. LanguageClient-neovim prints the following messages:

[LC] Error: Failure { jsonrpc: Some(V2), error: Error { code: InternalError, message: "method \"textDocument/completion\" did not reply", data: N
one }, id: Num(3) }
[LC] sending on a disconnected channel
[LC] sending on a disconnected channel

Last two are likely related to the gopls process exiting.

Build info

golang.org/x/tools/gopls v0.3.3
    golang.org/x/tools/[email protected] h1:mTFqRDJQmpSsgDDWvbtGnSva1z9uX2XcDszSWa6DhBQ=
    github.com/BurntSushi/[email protected] h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
    github.com/sergi/[email protected] h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
    golang.org/x/[email protected] h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
    golang.org/x/[email protected] h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
    golang.org/x/[email protected] h1:OX66ZzpltgCOuBSGdaeT77hS2z3ub2AB+EuGxvGRBLE=
    golang.org/x/[email protected] h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
    honnef.co/go/[email protected] h1:sXmLre5bzIR6ypkjXCDI3jHPssRhc8KD/Ome589sc3U=
    mvdan.cc/xurls/[email protected] h1:KaMb5GLhlcSX+e+qhbRJODnUUBvlw01jt4yrjFIHAuA=

Go info

go version go1.14 linux/amd64

GO111MODULE=""
GOARCH="amd64"
GOBIN="/home/foxcpp/.go/bin"
GOCACHE="/home/foxcpp/.cache/go-build"
GOENV="/home/foxcpp/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/foxcpp/.go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/foxcpp/gopls-bug/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build364981597=/tmp/go-build -gno-record-gcc-switches"

[gopherbot]

Thank you for filing a gopls issue! Please take a look at the Troubleshooting guide, and make sure that you have provided all of the relevant information here.

[foxcpp]

gopls.txt

gopls log with -rpc.trace. Also uploaded to https://hastebin.com/herurufoma for viewing convenience.

[muirdm]

Should be fixed by https://go-review.googlesource.com/c/tools/+/221020. The fix will be included in the next release. You can install from master in the meantime if you are hitting it a lot (it is triggered by the undeclared "a" identifier in the assignment.

[foxcpp]

Verified it is fixed at golang.org/x/tools/[email protected]. Thanks!

[stamblerre]

Thanks for confirming! I'll try to release gopls/v0.3.4 with this fix in the next few days.