sqlclosecheck|rowserrcheck: panic unreachable

[erane-opti]

Welcome

• Yes, I'm using a binary release within 2 latest releases. Only such installations are supported.
• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've read the typecheck section of the FAQ.
• Yes, I've tried with the standalone linter if available (e.g., gocritic, go vet, etc.).
• I agree to follow this project's Code of Conduct

How did you install golangci-lint?

Official binary

Description of the problem

Both linters calls go/types.Identical(..) which panics with unreachable
It seems (i'm not very sure) that this functions can't handle iter.Seq2

Version of golangci-lint

Details

$ golangci-lint --version
golangci-lint has version 2.11.4 built with go1.26.1 from 8f3b0c7e on 2026-03-22T17:35:14Z

Configuration

Details

golangci-lint run --enable sqlclosecheck --disable errcheck

golangci-lint run --enable rowserrcheck --disable errcheck

Go environment

Details

$ go version && go env
go1.25.8

Verbose output of running

Details

$ golangci-lint cache clean
$ golangci-lint  --enable rowserrcheck --disable errcheck
ERRO [runner] Panic: rowserrcheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable: goroutine 1365 [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({0x154c5a0?, 0x1b7cd30?})
        runtime/panic.go:860 +0x13a
go/types.(*comparer).identical(0x2d19833ce94e, {0x1b920a8?, 0x29ca010?}, {0x1b901c8?, 0x2d1983467880?}, 0x0)
        go/types/predicates.go:497 +0x805
go/types.(*comparer).identical(0x2d19833ce94e, {0x1b902e0?, 0x29ca000?}, {0x1b902e0?, 0x2d198273ab80?}, 0x0)
        go/types/predicates.go:311 +0x6ff
go/types.Identical(...)
        go/types/api_predicates.go:90
github.com/jingyugao/rowserrcheck/passes/rowserr.(*runner).getCallReturnsRow(0x2d19847e5ac0, {0x1ba2b50?, 0x2d19839a0b00})
        github.com/jingyugao/rowserrcheck@v1.1.1/passes/rowserr/rowserr.go:203 +0xcb
github.com/jingyugao/rowserrcheck/passes/rowserr.(*runner).errCallMissing(0x2d19847e5ac0, 0x1b901c8?, 0x2d1981c7e380?)
        github.com/jingyugao/rowserrcheck@v1.1.1/passes/rowserr/rowserr.go:112 +0x3a
github.com/jingyugao/rowserrcheck/passes/rowserr.runner.run({0x2d19820fe460, 0x2d198273ab80, 0x0, {0x1bb1110, 0x2d19836c3770}, 0x2d1983fae300, {0x2d198273ab70, 0x1, 0x1}}, 0x2d19820fe460, ...)
        github.com/jingyugao/rowserrcheck@v1.1.1/passes/rowserr/rowserr.go:103 +0x37d
github.com/golangci/golangci-lint/v2/pkg/golinters/rowserrcheck.New.NewAnalyzer.NewRun.func1(0x2d19820fe460)
        github.com/jingyugao/rowserrcheck@v1.1.1/passes/rowserr/rowserr.go:44 +0x13e
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze.func3(...)
        github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:180
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze(0x2d1983391380)
        github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:206 +0xb6b
github.com/golangci/golangci-lint/v2/pkg/timeutils.(*Stopwatch).TrackStage(0x2d19834c2140, {0x1825fb4, 0xc}, 0x2d19832eff10)
        github.com/golangci/golangci-lint/v2/pkg/timeutils/stopwatch.go:111 +0x44
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyzeSafe(0x2d1983391380?)
        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:107 +0x65
golang.org/x/sync/errgroup.(*Group).Go.func1()
        golang.org/x/sync@v0.20.0/errgroup/errgroup.go:93 +0x50
created by golang.org/x/sync/errgroup.(*Group).Go in goroutine 193
        golang.org/x/sync@v0.20.0/errgroup/errgroup.go:78 +0x95 
WARN [runner] Can't run linter goanalysis_metalinter: goanalysis_metalinter: rowserrcheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable 
ERRO Running error: can't run linter goanalysis_metalinter
goanalysis_metalinter: rowserrcheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable 

$ golangci-lint cache clean
$ golangci-lint  --enable rowserrcheck --disable errcheck
ERRO [runner] Panic: sqlclosecheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable: goroutine 1336 [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({0x154c5a0?, 0x1b7cd30?})
        runtime/panic.go:860 +0x13a
go/types.(*comparer).identical(0xddbac7fb9de, {0x1b920a8?, 0x29ca010?}, {0x1b901c8?, 0xddbad402c00?}, 0x0)
        go/types/predicates.go:497 +0x805
go/types.(*comparer).identical(0xddbac7fb9de, {0x1b902e0?, 0x29ca000?}, {0x1b902e0?, 0xddbacbcd450?}, 0x0)
        go/types/predicates.go:311 +0x6ff
go/types.Identical(...)
        go/types/api_predicates.go:90
github.com/ryanrolds/sqlclosecheck/pkg/analyzer.getTargetTypesValues(0xddbac111d80?, 0x29f5fe0?, {0xddbac5d46c0, 0x3, 0x4?})
        github.com/ryanrolds/sqlclosecheck@v0.6.0/pkg/analyzer/defer_only.go:189 +0x1c5
github.com/ryanrolds/sqlclosecheck/pkg/analyzer.(*deferOnlyAnalyzer).Run(0xddbac7fbb78?, 0xddbac8c4540)
        github.com/ryanrolds/sqlclosecheck@v0.6.0/pkg/analyzer/defer_only.go:69 +0x19e
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze.func3(...)
        github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:180
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyze(0xddbae745380)
        github.com/golangci/golangci-lint/v2/pkg/goanalysis/runner_checker.go:206 +0xb6b
github.com/golangci/golangci-lint/v2/pkg/timeutils.(*Stopwatch).TrackStage(0xddbad635720, {0x183750e, 0xd}, 0xddbacd92710)
        github.com/golangci/golangci-lint/v2/pkg/timeutils/stopwatch.go:111 +0x44
github.com/golangci/golangci-lint/v2/pkg/goanalysis.(*action).analyzeSafe(0xddbae745380?)
        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:107 +0x65
golang.org/x/sync/errgroup.(*Group).Go.func1()
        golang.org/x/sync@v0.20.0/errgroup/errgroup.go:93 +0x50
created by golang.org/x/sync/errgroup.(*Group).Go in goroutine 194
        golang.org/x/sync@v0.20.0/errgroup/errgroup.go:78 +0x95 
WARN [runner] Can't run linter goanalysis_metalinter: goanalysis_metalinter: sqlclosecheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable 
ERRO Running error: can't run linter goanalysis_metalinter
goanalysis_metalinter: sqlclosecheck: package "main" (isInitialPkg: true, needAnalyzeSource: true): unreachable 

A minimal reproducible example or link to a public repository

Details

package main

import (
	"context"
	"database/sql"
	"fmt"
	"iter"
	"sync"
)

type db struct {
	mu      sync.Mutex
	remotes map[string]*sql.DB
}

func (db *db) All() iter.Seq2[string, *sql.DB] {
	return func(yield func(string, *sql.DB) bool) {
		db.mu.Lock()
		defer db.mu.Unlock()
		for addr, r := range db.remotes {
			if !yield(addr, r) {
				return
			}
		}
	}
}

func (db *db) Foo(ctx context.Context) error {
	for addr, rem := range db.All() {
		rconn, err := rem.Conn(context.Background())
		if err != nil {
			return err
		}
		defer rconn.Close()

		rows, err := rconn.QueryContext(ctx, `SELECT * FROM foo`)
		if err != nil {
			return err
		}
		defer rows.Close()
		for rows.Next() {
			fmt.Println(rows.ColumnTypes())
		}
		if err := rows.Err(); err != nil {
			return err
		}
		fmt.Println(addr, rconn.PingContext(context.Background()))
	}
	return nil
}

func main() {
	d := &db{remotes: make(map[string]*sql.DB)}
	fmt.Println(d.Foo(context.Background()))
}

Validation

• Yes, I've included all information above (version, config, etc.).

Supporter

• I am a sponsor/backer of this project.

[ldez]

The problem doesn't seem related to iter.seq2 but to the fact to use defer inside a for.
These usages of defer doesn't work as expected, you should never do that.

Details

package main

import (
	"context"
	"database/sql"
	"fmt"
	"iter"
	"sync"
)

type db struct {
	mu      sync.Mutex
	remotes map[string]*sql.DB
}

func (db *db) All() iter.Seq2[string, *sql.DB] {
	return func(yield func(string, *sql.DB) bool) {
		db.mu.Lock()
		defer db.mu.Unlock()
		for addr, r := range db.remotes {
			if !yield(addr, r) {
				return
			}
		}
	}
}

func (db *db) Foo(ctx context.Context) error {
	for addr, rem := range db.All() {
		err := bar(ctx, rem, addr)
		if err != nil {
			return err
		}
	}
	return nil
}

func main() {
	d := &db{remotes: make(map[string]*sql.DB)}
	fmt.Println(d.Foo(context.Background()))
}

func bar(ctx context.Context, rem *sql.DB, addr string) error {
	rconn, err := rem.Conn(context.Background())
	if err != nil {
		return err
	}
	defer rconn.Close()

	rows, err := rconn.QueryContext(ctx, `SELECT * FROM foo`)
	if err != nil {
		return err
	}
	defer rows.Close()
	for rows.Next() {
		fmt.Println(rows.ColumnTypes())
	}
	if err := rows.Err(); err != nil {
		return err
	}
	fmt.Println(addr, rconn.PingContext(context.Background()))

	return nil
}

But there is a bug because those linters should not panic because of that, I'm working to fix that.

[erane-opti]

10x!
nitting: On my own complex code, The change I made to cause this is switching from ranging over map to ranging over iter.Seq2 . In both cases there is a defer x.Close() (test code), that was the red-herring. maybe that triggers a different flow in those linters...

But anyway, both works without defer

[ldez]

I opened PRs on the 2 linters to fix the bug.

• fix: panic with defer inside for loop ryanrolds/sqlclosecheck#50
• fix: panic referrers jingyugao/rowserrcheck#34