Unable to read go.mod when GOPATH is set to a folder inside the workspace.

[peterldowns]

What version of Go, VS Code & VS Code Go extension are you using?

Version Information

• Run go version to get version of Go from the VS Code integrated terminal. go version go1.18 darwin/arm64
• Run gopls -v version to get version of Gopls from the VS Code integrated terminal.

----------
golang.org/x/tools/gopls v0.8.1
    golang.org/x/tools/gopls@(devel)
    github.com/BurntSushi/[email protected]
    github.com/google/[email protected]
    github.com/sergi/[email protected]
    golang.org/x/[email protected]
    golang.org/x/[email protected]
    golang.org/x/[email protected]
    golang.org/x/[email protected]
    golang.org/x/[email protected]
    golang.org/x/[email protected]
    honnef.co/go/[email protected]
    mvdan.cc/[email protected]
    mvdan.cc/xurls/[email protected]
go: go1.18

• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders.

1.65.2
c722ca6c7eed3d7987c0d5c3df5c45f6b15e77d1
arm64

• Check your installed extensions to get the version of the VS Code Go extension v0.32.0
• Run Ctrl+Shift+P (Cmd+Shift+P on Mac OS) > Go: Locate Configured Go Tools command.

Checking configured tools....
GOBIN: undefined
toolsGopath: 
gopath: /Users/pld/code/gopls-repro-example/.go
GOROOT: /nix/store/adwrscl1v5qxbqv0l5f3wkljb0ha77mx-go-1.18/share/go
PATH: /Users/pld/code/gopls-repro-example/.go/bin:/nix/store/qc4fzcja2bs760vsqcsc6v28imjwy0wi-clang-wrapper-11.1.0/bin:/nix/store/rb559z09mrinv0w8mm1clss8s6p8k2if-clang-11.1.0/bin:/nix/store/8405gyg05szs83h883v84ds9h6x0i2ir-coreutils-9.0/bin:/nix/store/c0kfkdk2kad0dq0h981j8ffb1ngaf3y4-cctools-binutils-darwin-wrapper-949.0.1/bin:/nix/store/hwjqaci7cz4r7sxivsciil0ipfdg1nwf-cctools-binutils-darwin-949.0.1/bin:/nix/store/97mlg5qmdz36rpcz2dlc0rx79v1cbi8w-core-toolchains/bin:/nix/store/8405gyg05szs83h883v84ds9h6x0i2ir-coreutils-9.0/bin:/nix/store/b4f8lzhl4rjmssa557iz0j1l8i0mjyms-findutils-4.9.0/bin:/nix/store/kp0p49hzszmvs1lx2v6rs62aplkdxxa3-diffutils-3.8/bin:/nix/store/l8xw0jqwqrsbpzgbcmwkg58n2p1icc2s-gnused-4.8/bin:/nix/store/zdqvm614pwima18li99xrjyd82cwrq2p-gnugrep-3.7/bin:/nix/store/6w14k8a8arsizrlb8zsn9cyfhc44hh3q-gawk-5.1.1/bin:/nix/store/wkd35pvzjhb73qcv2njf524kf9ks9xki-gnutar-1.34/bin:/nix/store/r74vap0miki0j5y7d4lira1iwrjdyvw9-gzip-1.11/bin:/nix/store/raa1kmp83ry3yb184sqpyl1bk1h7bbjh-bzip2-1.0.6.0.2-bin/bin:/nix/store/1nvk71lbggjfvjh6gppb3kbkq60l88l2-gnumake-4.3/bin:/nix/store/czipazlkvql7n201a9l1jks8kzs0dlqa-bash-5.1-p16/bin:/nix/store/19kh8x7ilsh7539r8y2kc1rx99i37dk2-patch-2.7.6/bin:/nix/store/qqh82nrrhkj7gy3qqmmb2jbb961a0gxm-xz-5.2.5-bin/bin:/Users/pld/.bin:/opt/homebrew/bin:/opt/homebrew/sbin:/Users/pld/.nix-profile/bin:/run/current-system/sw/bin:/nix/var/nix/profiles/default/bin:/usr/local/bin:/usr/bin:/usr/sbin:/bin:/sbin

	go:	/nix/store/97mlg5qmdz36rpcz2dlc0rx79v1cbi8w-core-toolchains/bin/go: go version go1.18 darwin/arm64

	go-outline:	/nix/store/97mlg5qmdz36rpcz2dlc0rx79v1cbi8w-core-toolchains/bin/go-outline	(version: (devel) built with go: go1.17.7)
	gotests:	not installed
	gomodifytags:	not installed
	impl:	not installed
	goplay:	not installed
	staticcheck:	not installed
	gopls:	/nix/store/97mlg5qmdz36rpcz2dlc0rx79v1cbi8w-core-toolchains/bin/gopls	(version: (devel) built with go: go1.18)

go env
Workspace Folder (gopls-repro-example): /Users/pld/code/gopls-repro-example
	GO111MODULE=""
	GOARCH="arm64"
	GOBIN=""
	GOCACHE="/Users/pld/Library/Caches/go-build"
	GOENV="/Users/pld/Library/Application Support/go/env"
	GOEXE=""
	GOEXPERIMENT=""
	GOFLAGS=""
	GOHOSTARCH="arm64"
	GOHOSTOS="darwin"
	GOINSECURE=""
	GOMODCACHE="/Users/pld/code/gopls-repro-example/.go/pkg/mod"
	GONOPROXY=""
	GONOSUMDB=""
	GOOS="darwin"
	GOPATH="/Users/pld/code/gopls-repro-example/.go"
	GOPRIVATE=""
	GOPROXY="https://proxy.golang.org,direct"
	GOROOT="/nix/store/adwrscl1v5qxbqv0l5f3wkljb0ha77mx-go-1.18/share/go"
	GOSUMDB="sum.golang.org"
	GOTMPDIR=""
	GOTOOLDIR="/nix/store/adwrscl1v5qxbqv0l5f3wkljb0ha77mx-go-1.18/share/go/pkg/tool/darwin_arm64"
	GOVCS=""
	GOVERSION="go1.18"
	GCCGO="gccgo"
	AR="ar"
	CC="clang"
	CXX="clang++"
	CGO_ENABLED="1"
	GOMOD="/dev/null"
	GOWORK="/Users/pld/code/gopls-repro-example/go.work"
	CGO_CFLAGS="-g -O2"
	CGO_CPPFLAGS=""
	CGO_CXXFLAGS="-g -O2"
	CGO_FFLAGS="-g -O2"
	CGO_LDFLAGS="-g -O2"
	PKG_CONFIG="pkg-config"
	GOGCCFLAGS="-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/1_/ryk53sgj7jvc7l7pdrpllrqh0000gn/T/go-build2290272961=/tmp/go-build -gno-record-gcc-switches -fno-common"

Share the Go related settings you have added/edited

{
  "go.autocompleteUnimportedPackages": true,
  "go.lintOnSave": "package",
  "go.buildOnSave": "off",
  "go.vetOnSave": "off",
  "go.useLanguageServer": true,
  "go.toolsManagement.autoUpdate": false,
  "go.toolsManagement.checkForUpdates": "off",
  "gopls": {
    "formatting.gofumpt": true,
    "formatting.local": "github.com/peterldowns/gopls-repro-example",
    "build.directoryFilters": ["-", "+backend"],
    "build.experimentalWorkspaceModule": true
  },
  "[go]": {
    "editor.formatOnSave": true
  }
}

Describe the bug

When $GOPATH is set to a folder within the workspace, the Go extension throws a huge number of errors about failing to resolve a .mod file. It also attempts to do a lot of file access which means that it makes the user wait before they can do things like jump-to-definition or see their files autoformat on save. The error messages read like this:

Failed while handling 'onDidOpenTextDocument': EntryNotFound (FileSystemError): Unable to read file '/Users/pld/code/gopls-repro-example/.go/pkg/mod/go.mod' (Error: Unable to resolve nonexistent file '/Users/pld/code/gopls-repro-example/.go/pkg/mod/go.mod')
Failed while handling 'FileSystemWatcher.onDidCreate': EntryNotFound (FileSystemError): Unable to read file '/Users/pld/code/gopls-repro-example/.go/pkg/mod/go.mod' (Error: Unable to resolve nonexistent file '/Users/pld/code/gopls-repro-example/.go/pkg/mod/go.mod')

Instead, I would expect there to be no errors thrown and for all extension functionality to remain unaffected.

Steps to reproduce the behavior:

The key to triggering the issue seems to be setting $GOPATH to a folder inside the repository where VSCode is launched. I have provided an example repository with instructions in the README for how to reproduce the issue:

https://github.com/peterldowns/gopls-repro-example#vscode-go-reporting-unable-to-read-file-gomod-in-gomodcache

Screenshots or recordings

[hyangah]

Thanks for the thorough description of the repro case. I greatly appreciate your effort! @peterldowns

I think this error message is coming from https://github.com/golang/vscode-go/blob/78cc836ad4fc25aae2318c92249db2275334257c/src/goTest/explore.ts#L148

We should

• [ ] stop scanning the module cache directory
• [ ] investigate why this code was repeatedly run and why the code is looking for the non-existent go.mod file.
• [ ] stop outputting this error message

[peterldowns]

@hyangah glad to hear that the repro was worth the effort 🙇 I should say that we were able to work around this bug by simply moving the $GOPATH to a directory outside of our repo, so the urgency / importance is low. I just wanted to report it because the failure behavior was surprising and unexpected. Thank you again for all of your hard work and for the wonderful tools that you provide.

[stefanba3]

I am running into this issue with a different scenario: We use self-contained devbox environments with Go and all Go modules and tooling in the .devbox/virtenv folder. Frequently, this folder is in a vscode workspace folder, as a result we get these same symptoms described in this issue. Adding here in case it helps inform the priority of fixing this.