x/tools/gopls: misleading error message when having multiple workspace folders and using build tag

[hyangah]

gopls version

v0.12.2 (or v0.12.1)

go env

go env

 go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/hakim/Library/Caches/go-build"
GOENV="/Users/hakim/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/hakim/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/hakim/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.20.3"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/hakim/projects/tmp-misleading/mod1/go.mod"
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 -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/5p/zn7ykc111kn3lm09h_47mz2w001py5/T/go-build89764978=/tmp/go-build -gno-record-gcc-switches -fno-common"

gopls stats

gopls stats 
Initializing workspace...     done (281.462653ms)
Gathering bug reports...      done (368.227003ms)
Querying memstats...          done (4.590305ms)
Querying workspace stats...   done (716.432µs)
Collecting directory info...  done (186.099µs)
{
  "BugReports": [],
  "CacheDir": "/Users/hakim/Library/Caches/gopls/309eafdc",
  "DirStats": {
    "Files": 4,
    "TestdataFiles": 0,
    "GoFiles": 2,
    "ModFiles": 1,
    "Dirs": 1
  },
  "GOARCH": "amd64",
  "GOOS": "darwin",
  "GOPLSCACHE": "",
  "GoVersion": "go1.20.3",
  "GoplsVersion": "v0.12.1",
  "InitialWorkspaceLoadDuration": "281.462653ms",
  "MemStats": {
    "HeapAlloc": 9656168,
    "HeapInUse": 15237120,
    "TotalAlloc": 36597232
  },
  "WorkspaceStats": {
    "Files": {
      "Total": 447,
      "Largest": 201909,
      "Errs": 0
    },
    "Views": [
      {
        "GoCommandVersion": "go1.20.3",
        "AllPackages": {
          "Packages": 48,
          "LargestPackage": 132,
          "CompiledGoFiles": 444,
          "Modules": 2
        },
        "WorkspacePackages": {
          "Packages": 1,
          "LargestPackage": 1,
          "CompiledGoFiles": 1,
          "Modules": 1
        },
        "Diagnostics": 0
      }
    ]
  }
}

What did you do?

git clone https://github.com/hyangah/tmp-misleading
cd tmp-misleading/mod1
code .

Then, from the VS Code window open with the setting, open buildtag.go which has //go:build tag.

What did you expect to see?

Usual build-tag related error message on the package line

What did you see instead?

"This file is within module ".", which is not included in your workspace.
To fix this problem, you can add a go.work file that uses this directory.
See the documentation for more information on setting up your workspace:
https://github.com/golang/tools/blob/master/gopls/doc/workspace.md.go list"

[findleyr]

Thanks. We should improve this heuristic.

Milestoning for v0.12.4.

[gopherbot]

Change https://go.dev/cl/588941 mentions this issue: gopls/internal/cache: use a better view in viewOfLocked