name: "bool",
		t: func() {
			var a bool
			for i := 0; i < mods; i++ {
				a = !a
				runtime.Gosched()
			}
		},
		pointerT: func() {
			a := func() *bool { return new(bool) }()
			for i := 0; i < mods; i++ {
				*a = !*a
				runtime.Gosched()
			}
		},
		arrayT: func() {
			a := [length]bool{}
			for i := 0; i < mods; i++ {
				for j := 0; j < len(a); j++ {
					a[j] = !a[j]

				continue
			}
			if v != "none" {
				mods = append(mods, moduleInfo(ctx, rs, module.Version{Path: arg, Version: v}, mode, reuse))
			} else if cfg.BuildMod == "vendor" {
				// In vendor mode, we can't determine whether a missing module is “a
				// known dependency” because the module graph is incomplete.
				// Give a more explicit error message.
				mods = append(mods, &modinfo.ModulePublic{
					Path:  arg,

			// shortest to longest. Reverse them now.
			for i := 0; i < len(mods)/2; i++ {
				j := len(mods) - 1 - i
				mods[i], mods[j] = mods[j], mods[i]
				roots[i], roots[j] = roots[j], roots[i]
				dirs[i], dirs[j] = dirs[j], dirs[i]
			}
			return module.Version{}, "", "", nil, &AmbiguousImportError{importPath: path, Dirs: dirs, Modules: mods}
		}

		if len(sumErrMods) > 0 {
			for i := 0; i < len(sumErrMods)/2; i++ {

# dependencies through older versions of the main module.

go list -f '{{with .Module}}{{.Path}}{{with .Version}} {{.}}{{end}}{{end}}' all
cmp stdout pkgmods.txt

go list -m all
cmp stdout mods.txt

go mod graph
cmp stdout graph.txt

-- go.mod --
module golang.org/issue/root

go 1.12

replace (
	golang.org/issue/mirror v0.1.0 => ./mirror-v0.1.0
	golang.org/issue/pkg v0.1.0 => ./pkg-v0.1.0

	if err != nil {
		base.Fatal(err)
	}
	mods := mg.BuildList()
	// Use a slice of result channels, so that the output is deterministic.
	errsChans := make([]<-chan []error, len(mods))

	for i, mod := range mods {
		sem <- token{}
		errsc := make(chan []error, 1)
		errsChans[i] = errsc
		mod := mod // use a copy to avoid data races
		go func() {
			errsc <- verifyMod(ctx, mod)
			<-sem
		}()
	}

	ok := true

parenthesized note indicating that fact.

For example:

	$ go mod why golang.org/x/text/language golang.org/x/text/encoding
	# golang.org/x/text/language
	rsc.io/quote
	rsc.io/sampler
	golang.org/x/text/language

	# golang.org/x/text/encoding
	(main module does not need package golang.org/x/text/encoding)
	$

See https://golang.org/ref/mod#go-mod-why for more about 'go mod why'.
	`,
}

var (

	}

	// If there were explicit arguments, update go.mod and especially go.sum.
	// 'go mod download mod@version' is a useful way to add a sum without using
	// 'go get mod@version', which may have other side effects. We print this in
	// some error message hints.
	//
	// If we're in workspace mode, update go.work.sum with checksums for all of
	// the modules we downloaded that aren't already recorded. Since a requirement

# 'go mod why' should fail, since there is no main module to depend on anything.
! go mod why -m example.com/version
stderr '^go: go.mod file not found in current directory or any parent directory; see ''go help modules''$'

# 'go mod edit', 'go mod tidy', and 'go mod fmt' should fail:
# there is no go.mod file to edit.
! go mod tidy
stderr '^go: go.mod file not found in current directory or any parent directory; see ''go help modules''$'
! go mod edit -fmt

		// and do we need to pass a toolchain.Switcher in LoadPackages?
		// If so, think about saving the WriteGoMods for after the loop,
		// so we don't write some go.mods with the "before" toolchain
		// and others with the "after" toolchain. If nothing else, that
		// discrepancy could show up in auto-recorded toolchain lines.
		changed, err := modload.EditBuildList(ctx, nil, mustSelectFor[m])
		if err != nil {
			continue

	}
	goSum.m[mod] = append(goSum.m[mod], h)
}

// checkSumDB checks the mod, h pair against the Go checksum database.
// It calls base.Fatalf if the hash is to be rejected.
func checkSumDB(mod module.Version, h string) error {
	modWithoutSuffix := mod
	noun := "module"
	if before, found := strings.CutSuffix(mod.Version, "/go.mod"); found {