x/tools/gopls/internal/cache/methodsets: "missing object path for %s" bug in indexBuilder.build

[jacksoom]

#!stacks
"runtime.gopanic" && "methodsets.(*indexBuilder).build.func2:+12" ||
 "bug.Reportf" && "(*indexBuilder).build.func2.1:+1" || // off-by-one line due to telemetry bug
 "bug.Reportf" && "(*indexBuilder).build.func2:+32" ||  /* default case */
 "bug.Reportf" && "(*indexBuilder).build.func2:+28" /* method.Origin() != method */

Note that various cases of the refinement switch have been observed to have been reached.

Issue created by stacks.

		// Instantiations of generic methods don't have an
		// object path, so we use the generic.
		if p, err := objectpathFor(method.Origin()); err != nil {
			panic(err) // can't happen for a method of a package-level type
		} else {
			m.ObjectPath = b.string(string(p))
		}

First stack is here.

gopls version: v0.17.0-pre.2/go1.23.2
gopls flags:
update flags: proxy
extension version: 0.42.1
environment: Cursor darwin
initialization error: undefined
issue timestamp: Sat, 16 Nov 2024 15:11:16 GMT
restart history:
Sat, 16 Nov 2024 15:10:59 GMT: activation (enabled: true)

gopls stats -anon

{ "DirStats": { "Files": 5774, "TestdataFiles": 216, "GoFiles": 960, "ModFiles": 1, "Dirs": 516 }, "GOARCH": "arm64", "GOOS": "darwin", "GOPACKAGESDRIVER": "", "GOPLSCACHE": "", "GoVersion": "go1.23.2", "GoplsVersion": "v0.17.0-pre.2", "InitialWorkspaceLoadDuration": "1.603257166s", "MemStats": { "HeapAlloc": 318890328, "HeapInUse": 434987008, "TotalAlloc": 1358687472 }, "WorkspaceStats": { "Files": { "Total": 9784, "Largest": 4950165, "Errs": 0 }, "Views": [ { "GoCommandVersion": "go1.23.2", "AllPackages": { "Packages": 2191, "LargestPackage": 159, "CompiledGoFiles": 10309, "Modules": 322 }, "WorkspacePackages": { "Packages": 199, "LargestPackage": 54, "CompiledGoFiles": 1185, "Modules": 1 }, "Diagnostics": 0 } ] } }

Dups: yJIbcA 9nLJcw B-EmyA re0xQw VFXJYg MDN9RQ yO6-PA RUV5wg WIlwRw eH5YOA aDGiAQ GDWB-g TZ2CCA GOwIkg

[jacksoom]

[Info  - 7:38:35 PM] 2024/11/17 19:38:35 Created View (#1)
	directory=/Users/jacksoom/programer/pell/chain
	view_type="GoMod"
	root_dir="file:///Users/jacksoom/programer/pell/chain"
	go_version="go version go1.23.2 darwin/arm64"
	build_flags=[]
	env={GOOS:darwin GOARCH:arm64 GOCACHE:/Users/jacksoom/Library/Caches/go-build GOMODCACHE:/Users/jacksoom/programer/golang/pkg/mod GOPATH:/Users/jacksoom/programer/golang GOPRIVATE:github.com/0xPellNetwork/* GOFLAGS: GO111MODULE:on GOTOOLCHAIN:auto GOROOT:/Users/jacksoom/.goenv/versions/1.23.2 GoVersion:23 GoVersionOutput:go version go1.23.2 darwin/arm64
 ExplicitGOWORK: EffectiveGOPACKAGESDRIVER:}
	env_overlay=[]

[Info  - 7:38:36 PM] 2024/11/17 19:38:36 go/packages.Load golang/vscode-go#1
	view_id="1"
	snapshot=0
	directory=/Users/jacksoom/programer/pell/chain
	query=[/Users/jacksoom/programer/pell/chain/... builtin]
	packages=261
	duration=891.908667ms

panic: can't find path for func (github.com/cosmos/cosmos-sdk/x/authz.Authorization).ValidateBasic() error in github.com/cosmos/cosmos-sdk/x/authz

[jacksoom]

gopls(server) output log

[jacksoom]

go version go1.23.2 darwin/arm64
gopls version
golang.org/x/tools/gopls v0.17.0-pre.2

[jacksoom]

The crash appears to be specific to this gopls version. After switching to version 0.16.2. works fine right now.

[findleyr]

Thank you! We will fix this for the next prerelease. Very much appreciate the report.

[findleyr]

@jacksoom could you please possibly include the full panicking stack? The panic message alone is not necessarily easy to track down.

Edit: see #70418 (comment); --@adonovan

[findleyr]

@adonovan the panic here looks like the likely culprit:
https://cs.opensource.google/go/x/tools/+/master:gopls/internal/cache/methodsets/methodsets.go;l=232;drc=1d5e334177335fd58b8eee6f809b3589bf7371aa

I can certainly imagine that some combination of aliases, generics, embedding, and importing could result in an interface method that has no objectpath. However, in that case the question is why didn't this reproduce with v0.16.2, as I don't think this logic has changed recently.

[adonovan]

the panic here looks like the likely culprit:

Well spotted. We should probably always augment panic(err) calls with a distinct string to make these needles easier to find in the haystack.