x/tools/gopls: CodeAction: SEGV in internal/modindex.(*Index).Lookup

[firelizzard18]

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 go1.24.2 linux/amd64
• Run gopls -v version to get version of Gopls from the VS Code integrated terminal.
  Build info
  ----------
  golang.org/x/tools/gopls v0.19.0-pre.2
  golang.org/x/tools/gopls@v0.19.0-pre.2 h1:CUjqNCFGKHPMRZMd/tkBvtkae+eJuGNHOYsGpKxQNj4=
  github.com/BurntSushi/toml@v1.4.1-0.20240526193622-a339e1f7089c h1:pxW6RcqyfI9/kWtOwnv/G+AzdKuy2ZrqINhenH4HyNs=
  github.com/fatih/camelcase@v1.0.0 h1:hxNvNX/xYBp0ovncs8WyWZrOrpBNub/JfaMvbURyft8=
  github.com/fatih/gomodifytags@v1.17.1-0.20250423142747-f3939df9aa3c h1:dDSgAjoOMp8da3egfz0t2S+t8RGOpEmEXZubcGuc0Bg=
  github.com/fatih/structtag@v1.2.0 h1:/OdNE99OxoI/PqaW/SuSK9uxxT3f/tcSZgon/ssNSx4=
  github.com/google/go-cmp@v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
  golang.org/x/exp/typeparams@v0.0.0-20250218142911-aa4b98e5adaa h1:Br3+0EZZohShrmVVc85znGpxw7Ca8hsUJlrdT/JQGw8=
  golang.org/x/mod@v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
  golang.org/x/sync@v0.14.0 h1:woo0S4Yywslg6hp4eUFjTVOyKt0RookbpAHG4c1HmhQ=
  golang.org/x/telemetry@v0.0.0-20250417124945-06ef541f3fa3 h1:RXY2+rSHXvxO2Y+gKrPjYVaEoGOqh3VEXFhnWAt1Irg=
  golang.org/x/text@v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
  golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849 h1:y+3SPx7RmIoU/DCRF+k0+AhC/jvtMWEzb2m5j2j4OWA=
  golang.org/x/vuln@v1.1.4 h1:Ju8QsuyhX3Hk8ma3CesTbO8vfJD9EvUBgHvkxHBzj0I=
  honnef.co/go/tools@v0.7.0-0.dev.0.20250523013057-bbc2f4dd71ea h1:fj8r9irJSpolAGUdZBxJIRY3lLc4jH2Dt4lwnWyWwpw=
  mvdan.cc/gofumpt@v0.7.0 h1:bg91ttqXmi9y2xawvkuMXyvAA/1ZGJqYAEGjXuP0JXU=
  mvdan.cc/xurls/v2@v2.6.0 h1:3NTZpeTxYVWNSokW3MKeyVkz/j7uYXYiMtXRUfmjbgI=
  go: go1.24.3
• Run code -v or code-insiders -v to get version of VS Code or VS Code Insiders.
  • 1.100.1
    91fa95bccb027ece6a968589bb1d662fa9c8e170
    x64
• Check your installed extensions to get the version of the VS Code Go extension
  • 0.47.3
• Run Ctrl+Shift+P (Cmd+Shift+P on Mac OS) > Go: Locate Configured Go Tools command.

  • Tools Configuration

Environment

GOBIN: undefined
toolsGopath:
gopath: /home/firelizzard/go
GOROOT: /usr/lib/go
PATH: /usr/local/sbin:/usr/local/bin:/usr/bin:/opt/bin:/usr/lib/llvm/19/bin:/usr/lib/llvm/18/bin:/home/firelizzard/.local/bin:/home/firelizzard/go/bin:/home/firelizzard/go/bin:/home/firelizzard/.bin

Tools

go:	/usr/bin/go: go version go1.24.2 linux/amd64

gopls:	/home/firelizzard/go/bin/gopls	(version: v0.19.0-pre.2 built with go: go1.24.3)
gotests:	/home/firelizzard/go/bin/gotests	(version: v1.6.0 built with go: go1.24.1)
impl:	/home/firelizzard/go/bin/impl	(version: v1.4.0 built with go: go1.24.1)
goplay:	/home/firelizzard/go/bin/goplay	(version: v1.0.0 built with go: go1.24.1)
dlv:	/home/firelizzard/go/bin/dlv	(version: v1.24.1 built with go: go1.24.1)
golint:	/home/firelizzard/go/bin/golint	(version: v0.0.0-20241112194109-818c5a804067 built with go: go1.24.1)

Go env

Workspace Folder (hermes): /home/firelizzard/src/misc/hermes

AR='ar'
CC='x86_64-pc-linux-gnu-gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='x86_64-pc-linux-gnu-g++'
GCCGO='/usr/bin/gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/firelizzard/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/firelizzard/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build509238208=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/home/firelizzard/src/misc/hermes/go.mod'
GOMODCACHE='/home/firelizzard/go/pkg/mod'
GONOPROXY='github.com/C3Rules/Go-DTRules'
GONOSUMDB='github.com/C3Rules/Go-DTRules'
GOOS='linux'
GOPATH='/home/firelizzard/go'
GOPRIVATE='github.com/C3Rules/Go-DTRules'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/lib/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='on'
GOTELEMETRYDIR='/home/firelizzard/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='local'
GOTOOLDIR='/usr/lib/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.2'
GOWORK=''
PKG_CONFIG='pkg-config'

Share the Go related settings you have added/edited

settings

{
    "go.useLanguageServer": true,
    "go.vetFlags": [
        "-composites=false"
    ],
    // "go.formatTool": "goimports",
    "go.toolsEnvVars": {
        // "CGO_ENABLED": "0",
        // "GOOS": "linux"
        // "GOOS": "windows"
    },
    "go.delveConfig": {
        "debugAdapter": "dlv-dap",
        "hideSystemGoroutines": true,
    },
    "go.playground": {
        "openbrowser": false,
        "share": false,
        "run": true
    },
    "go.testFlags": [
        "-count=1",
        // "-cpu=1",
        // "-short",
        // "-test.validate.full"
    ],
    "go.testTimeout": "30m",
    "go.lintOnSave": "off",
    "go.testExplorer.packageDisplayMode": "nested",
    "[go]": {
        // "editor.formatOnSave": false,
    },
    "gopls": {
        // "ui.documentation.hoverKind": "SynopsisDocumentation",
        "ui.codelenses": {
            "gc_details": true
        },
        "ui.diagnostic.analyses": {
            "copylocks": false
        }
    },
    "go.languageServerFlags": ["-rpc.trace"],
    "go.lintTool": "golint",
    "go.inlayHints.parameterNames": true,
    "go.inlayHints.functionTypeParameters": true,
    "go.inlayHints.constantValues": true,
    "go.inlayHints.compositeLiteralFields": true,
    "go.toolsManagement.autoUpdate": true,
    "go.coverOnTestPackage": false,
}

Describe the bug

Gopls crashes when I interact with &cobra.Command{}. Specifically the cobra part, I wanted to use it to insert the import.

Steps to reproduce the behavior:

1. Click on "cobra".

Screenshots or recordings

The log file is in hermes.zip. I seem to be able to reproduce it just by restarting gopls. It's possible I'm running a version of gopls built from one of my CLs but gopls version shows golang.org/x/tools/gopls v0.19.0-pre.2 so I think not.

2025-06-06.16-51-05.mp4

[firelizzard18]

The automated reporter didn't work. I think the log file is too big.

[firelizzard18]

I ran sudo rm -rf ~/go/pkg (some stuff in there was owned by root, probably due to running a job with docker) and rebuilt gopls. It was crashing on one particular file and after this it stopped crashing for that file, so that may have been the issue.

[adonovan]

Thanks. The salient portion of the log is this:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0xc3cc4d]

goroutine 91117 gp=0xc00e431180 m=29 mp=0xc000601808 [running]:
panic({0x1104340?, 0x1e21940?})
	/home/firelizzard/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.linux-amd64/src/runtime/panic.go:811 +0x168 fp=0xc014735b38 sp=0xc014735a88 pc=0x47a588
runtime.panicmem(...)
	/home/firelizzard/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.linux-amd64/src/runtime/panic.go:262
runtime.sigpanic()
	/home/firelizzard/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.linux-amd64/src/runtime/signal_unix.go:925 +0x359 fp=0xc014735b98 sp=0xc014735b38 pc=0x47cb99
golang.org/x/tools/internal/modindex.(*Index).Lookup(0x0, {0xc026ea2b9b, 0x5}, {0xc026ea2bb0, 0x7}, 0x0)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/modindex/lookup.go:71 +0x4d fp=0xc014735d90 sp=0xc014735b98 pc=0xc3cc4d
golang.org/x/tools/internal/modindex.(*Index).LookupAll(0x0, {0xc026ea2b9b, 0x5}, {0xc012163d40?, 0x10a0a40?, 0x0?})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/modindex/lookup.go:45 +0xc9 fp=0xc014735ee8 sp=0xc014735d90 pc=0xc3c689
golang.org/x/tools/gopls/internal/cache.(*goplsSource).resolveCacheReferences(0xc010b5ce60, 0xc018202420)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/cache/source.go:148 +0x1d5 fp=0xc014736200 sp=0xc014735ee8 pc=0xd757d5
golang.org/x/tools/gopls/internal/cache.(*goplsSource).ResolveReferences(0xc010b5ce60, {0x15e6c58?, 0xc018202360?}, {0xc00f31ea07?, 0x0?}, 0xc018202210)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/cache/source.go:70 +0x14d fp=0xc014736490 sp=0xc014736200 pc=0xd752cd
golang.org/x/tools/internal/imports.addExternalCandidates({0x15e6c58?, 0xc008d409f0?}, 0xc014736600, 0xc018202210, {0xc00f31ea07, 0x32})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/imports/fix.go:1193 +0xbd fp=0xc014736598 sp=0xc014736490 pc=0xc4f39d
golang.org/x/tools/internal/imports.getFixesWithSource({0x15e6c58, 0xc008d409f0}, 0xc01472ccc0, 0xc032f6c8c0, {0xc00f31ea07, 0x32}, {0xc000590750, 0xb}, 0x0, {0x15e1728, ...})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/imports/fix.go:654 +0x477 fp=0xc014736760 sp=0xc014736598 pc=0xc4bbb7
golang.org/x/tools/internal/imports.FixImports({0x15e6c58?, 0xc008d40600?}, {0xc00f31ea07, 0x32}, {0xc0093ff540, 0x29, 0x40}, {0xc000590750, 0xb}, 0x0, ...)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/imports/imports.go:88 +0x1ce fp=0xc014736818 sp=0xc014736760 pc=0xc53d8e
golang.org/x/tools/gopls/internal/golang.computeImportEdits({0x15e6c58, 0xc008d40600}, 0xc02f41e480, 0xc026d37b00, 0xc008d40960)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/format.go:154 +0x252 fp=0xc014736938 sp=0xc014736818 pc=0xe3f872
golang.org/x/tools/gopls/internal/golang.allImportsFixes.func1({0x15e6c58?, 0xc008d40600?}, 0x93dfcb5168786c1b?)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/format.go:120 +0x4a fp=0xc014736988 sp=0xc014736938 pc=0xe3f56a
golang.org/x/tools/gopls/internal/cache.(*importsState).runProcessEnvFunc(0xc006684a50, {0x15e6c58?, 0xc008d404e0?}, 0xc026d37b00, 0xc013fb2b70)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/cache/imports.go:271 +0x334 fp=0xc014736af0 sp=0xc014736988 pc=0xd4b614
golang.org/x/tools/gopls/internal/cache.(*Snapshot).RunProcessEnvFunc(...)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/cache/view.go:414
golang.org/x/tools/gopls/internal/golang.allImportsFixes({0x15e6c58?, 0xc008d40090?}, 0xc026d37b00, 0xc02f41e480)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/format.go:119 +0x107 fp=0xc014736bc8 sp=0xc014736af0 pc=0xe3f3a7
golang.org/x/tools/gopls/internal/golang.(*allImportsFixesResult).init(0xc01472cc00, {0x15e6c58, 0xc008d40090}, 0xc032f6c820)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/codeaction.go:377 +0x50 fp=0xc014736c88 sp=0xc014736bc8 pc=0xe1e2d0
golang.org/x/tools/gopls/internal/golang.lazyInit[...]({0x15e6c58, 0xc008d40090}, 0xc032f6c820)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/codeaction.go:219 +0xa6 fp=0xc014736ce8 sp=0xc014736c88 pc=0xea6b26
golang.org/x/tools/gopls/internal/golang.quickFix({0x15e6c58?, 0xc008d40090?}, 0xc032f6c820)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/codeaction.go:298 +0x51 fp=0xc014736e98 sp=0xc014736ce8 pc=0xe1d931
golang.org/x/tools/gopls/internal/golang.CodeActions({0x15e6c58, 0xc008d40090}, 0xc026d37b00, {0x15ebbb0, 0xc01290b200}, {{0x13fb3430?, 0xc0?}, {0x58579a?, 0x0?}}, {0xc02f41ea20, ...}, ...)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/golang/codeaction.go:107 +0x625 fp=0xc014737370 sp=0xc014736e98 pc=0xe1cf85
golang.org/x/tools/gopls/internal/server.(*server).CodeAction(0xc00036a300, {0x15e6c58?, 0xc0096cc690?}, 0xc00037cee0)
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/server/code_action.go:177 +0x5a9 fp=0xc0147378e0 sp=0xc014737370 pc=0xef4d29
golang.org/x/tools/gopls/internal/protocol.serverDispatch({0x15e6c58, 0xc0096cc690}, {0x1606250, 0xc00036a300}, 0xc00b06df20, {0x15e6e50, 0xc013979a40})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/protocol/tsserver.go:330 +0x239d fp=0xc014737bc0 sp=0xc0147378e0 pc=0x7cdd5d
golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.ServerHandler.func4({0x15e6c58, 0xc0096cc690}, 0xc00b06df20, {0x15e6e50, 0xc013979a40})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/protocol/protocol.go:159 +0x85 fp=0xc014737c20 sp=0xc014737bc0 pc=0xf2f345
golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.handshaker.func5({0x15e6c58, 0xc0096cc690}, 0xc00b06df20, {0x15e6e50, 0xc013979a40})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools/gopls@v0.19.0-pre.2/internal/lsprpc/lsprpc.go:542 +0x909 fp=0xc014737ef8 sp=0xc014737c20 pc=0xf2f0a9
golang.org/x/tools/gopls/internal/protocol.Handlers.MustReplyHandler.func1({0x15e6c58, 0xc0096cc690}, 0xc01e49f488, {0x15e6e50, 0xc013979a40})
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/jsonrpc2/handler.go:35 +0xc6 fp=0xc014737f50 sp=0xc014737ef8 pc=0x7bd606
golang.org/x/tools/gopls/internal/protocol.Handlers.AsyncHandler.func2.2()
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/jsonrpc2/handler.go:104 +0x96 fp=0xc014737fe0 sp=0xc014737f50 pc=0x7bd436
runtime.goexit({})
	/home/firelizzard/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.24.3.linux-amd64/src/runtime/asm_amd64.s:1700 +0x1 fp=0xc014737fe8 sp=0xc014737fe0 pc=0x482e61
created by golang.org/x/tools/gopls/internal/protocol.Handlers.AsyncHandler.func2 in goroutine 97
	/home/firelizzard/go/pkg/mod/golang.org/x/tools@v0.33.1-0.20250604180551-4d89d8aef849/internal/jsonrpc2/handler.go:101 +0x22f