Using metalinter autosave and gopls is slow

[hnnsgstfssn]

What did you do? (required: The issue will be closed when not provided)

Open a Go source file in a module, then save the file with g:go_metalinter_command=gopls and g:go_metalinter_autosave=1.

What did you expect to happen?

That it would take <1s or that the linter runs asyncronously.

What happened instead?

Input is frozen until the linter passes or fails. This takes ~10s (see profile.log). Manually running :GoMetaLinter takes a fraction of a second.

Configuration (MUST fill this out):

vim-go version: 7b43988 (master)

vimrc you used to reproduce:

vimrc

set nocompatible
call plug#begin('~/.config/nvim/plugged')
Plug 'fatih/vim-go', { 'branch': 'master', 'do': ':GoUpdateBinaries' }
call plug#end()
let g:go_metalinter_command = "gopls"
let g:go_metalinter_autosave = 1

Vim version (first three lines from :version):

NVIM v0.4.3
Build type: Release
LuaJIT 2.0.5

Go version (go version):

go version go1.14.4 linux/amd64

Go environment

go env Output:

GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/x/.cache/go-build"
GOENV="/home/x/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/x/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="0"
GOMOD="/dev/null"
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build306055507=/tmp/go-build -gno-record-gcc-switches"

gopls version

gopls version Output:

golang.org/x/tools/gopls 0.4.3
    golang.org/x/tools/[email protected] h1:irz7Q+XdHNECamFKbNWKvMV2Ak6zBbwdwbZndG4545I=

[bhcleek]

The gopls logs will be the most useful here. Can you open the file, execute :let g:go_debug=['lsp'], save your file, and provide the complete contents of the resulting __GOLSP_LOG__ window here?

[hnnsgstfssn]

Absolutely, I had to add let g:go_debug=['lsp'] to my vimrc for it to start gopls with debug enabled, instead of setting after starting the session. golsp.log is the resulting output after opening the file with debug enabled and then saving it.

FWIW the following steps recreates a minimal module that I'm using to test this.

mkdir a; cd a
go mod init a
cat <<EOF>main.go
package main

import "fmt"

func main() {
  fmt.Println("hello")
}
EOF

[bhcleek]

Absolutely, I had to add let g:go_debug=['lsp'] to my vimrc for it to start gopls with debug enabled

FWIW, let g:go_debug=['lsp'] does not have to be in your vimrc. You can set it at any time to see the request and responses to sent to and received from gopls after it's set.

In any case, I think I see what's going on here. I should have some time improve the experience next weekend.