x/tools/gopls: show error message if nested module is not root

[ymotongpoo]

Please answer these questions before submitting your issue. Thanks!

What did you do?

I was developing a new package on VSCode + gopls and found VSCode constantly shows undefined error though they are defined in the package.

Reproducible code sets are here.
https://github.com/GoogleCloudPlatform/opentelemetry-operations-go/tree/b628ab9ba3d8fe893ed9dcb63d07a75fe56a8b10

What did you expect to see?

The following types are resolved without errors:

• options in metrics.go L69
• labelValue in metrics.go L90 and so on. (In newMetricsExporter)
• sanitize in metrics.go L102

What did you see instead?

Undefined errors on each types.

Build info

golang.org/x/tools/gopls v0.3.4
    golang.org/x/tools/[email protected] h1:4GC7q/pXQ/tsxHBGVdsMdlB4gCxVC06m/7rIXg1Px4E=
    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:hKrQy/q8/Xivoqgw6nGiz1jqpn1WGBLDcWLZwW0983E=
    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 go1.13.9 linux/amd64

GO111MODULE="auto"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/ymotongpoo/.cache/go-build"
GOENV="/home/ymotongpoo/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/ymotongpoo/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/go/go1.13.9"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/go/go1.13.9/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/ymotongpoo/src/projects/opentelemetry-operations-go/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-build957972558=/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.

[stamblerre]

Thanks for the detailed report! This issue is due to the fact that the metrics directory is a nested module. Right now, gopls requires you to open the module you are working on as your workspace root, so since https://github.com/GoogleCloudPlatform/opentelemetry-operations-go is also a module, gopls is treating that as the root. If you open github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/metrics as your workspace root, gopls will treat that as your module and the types should be resolved.

I know that this is not the ideal behavior, and we are working on resolving this issue for gopls/v0.5.0. You can track progress for that here: https://github.com/golang/go/milestone/138. Closing this issue since this is already tracked.

[stamblerre]

Actually, I'll reopen this issue for now - we should show a better error message in this case.

[ymotongpoo]

@stamblerre Thank you for the work around. It worked!

[stamblerre]

We are moving towards eliminating this issue with #37720 coming the near future, so I think this is no longer necessary.

[ymotongpoo]

Awesome!