Panic "slice bounds out of range" when using a helper function with log/slog #108
Description
I'm getting an unexpected panic when executing loggercheck via golangci-lint.
$ golangci-lint run
ERRO [runner] Panic: loggercheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): runtime error: slice bounds out of range [2:1]: goroutine 2179 [running]:
runtime/debug.Stack()
runtime/debug/stack.go:26 +0x5e
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyzeSafe.func1()
github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_action.go:55 +0x257
panic({0x159ed80?, 0xc0001347e0?})
runtime/panic.go:792 +0x132
github.com/timonwong/loggercheck/internal/checkers.ExecuteChecker({0x1b7ce20, 0x281f100}, 0xc001e60380, {0xc000552980?, 0xc0024bca20?, 0xc0005a9340?}, {0x8?, 0x0?})
github.com/timonwong/[email protected]/internal/checkers/checker.go:37 +0x36f
github.com/timonwong/loggercheck.(*loggercheck).checkLoggerArguments(0xc000ee32d0, 0xc001e60380, 0xc000552980)
github.com/timonwong/[email protected]/loggercheck.go:138 +0xb6
github.com/timonwong/loggercheck.(*loggercheck).run.func1({0x1b757b8?, 0xc000552980})
github.com/timonwong/[email protected]/loggercheck.go:201 +0x76
golang.org/x/tools/go/ast/inspector.(*Inspector).Preorder(0xc00090f2d8, {0xc0004bcb58?, 0xc000bf1590?, 0x40c06b?}, 0xc001321b40)
golang.org/x/[email protected]/go/ast/inspector/inspector.go:122 +0x91
github.com/timonwong/loggercheck.(*loggercheck).run(0xc000ee32d0, 0xc001e60380)
github.com/timonwong/[email protected]/loggercheck.go:192 +0xac
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze.func3(...)
github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:182
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze(0xc001a0d7e0)
github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:208 +0xb62
github.com/golangci/golangci-lint/v2/pkg/timeutils.(*Stopwatch).TrackStage(0xc003682960, {0x1676c75, 0xb}, 0xc001d92710)
github.com/golangci/golangci-lint/v2/pkg/timeutils/stopwatch.go:111 +0x44
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyzeSafe(0xc001a0d7e0?)
github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_action.go:59 +0x71
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*loadingPackage).analyze.func2()
github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_loadingpackage.go:106 +0x65
golang.org/x/sync/errgroup.(*Group).Go.func1()
golang.org/x/[email protected]/errgroup/errgroup.go:93 +0x50
created by golang.org/x/sync/errgroup.(*Group).Go in goroutine 517
golang.org/x/[email protected]/errgroup/errgroup.go:78 +0x93
WARN [runner] Can't run linter goanalysis_metalinter: goanalysis_metalinter: loggercheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): runtime error: slice bounds out of range [2:1]
ERRO Running error: can't run linter goanalysis_metalinter
goanalysis_metalinter: loggercheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): runtime error: slice bounds out of range [2:1]
Here is the minimum required to replicate:
main.go
package main
import (
"context"
"log/slog"
)
func main() {
slog.ErrorContext(fn())
}
func fn() (context.Context, string) {
return nil, "test"
}.golangci.yaml
version: "2"
linters:
default: all
My environment:
$ golangci-lint --version
golangci-lint has version 2.3.0 built with go1.24.4 from 364a4bbe on 2025-07-21T14:49:16Z
Same issue also exists in sloglint.