if i == nil {
		return modFile != nil
	}

	if i.dataNeedsFix {
		return true
	}

	if modFile.Module == nil {
		if i.module != (module.Version{}) {
			return true
		}
	} else if modFile.Module.Mod != i.module {
		return true
	}

	var goV, toolchain string
	if modFile.Go != nil {
		goV = modFile.Go.Version
	}
	if modFile.Toolchain != nil {

		base.Fatalf(`go: invalid module path "%v": %v`, modPath, invalidMajorVersionMsg)
	}

	fmt.Fprintf(os.Stderr, "go: creating new go.mod: module %s\n", modPath)
	modFile := new(modfile.File)
	modFile.AddModuleStmt(modPath)
	MainModules = makeMainModules([]module.Version{modFile.Module.Mod}, []string{modRoot}, []*modfile.File{modFile}, []*modFileIndex{nil}, nil)

# Test that -modfile=path/to/go.mod is rejected in workspace mode.

! go list -m -modfile=./a/go.alt.mod
stderr 'go: -modfile cannot be used in workspace mode'

env GOFLAGS=-modfile=./a/go.alt.mod
! go list -m
stderr 'go: -modfile cannot be used in workspace mode'

-- go.work --
go 1.20

use (
    ./a
)

-- a/go.mod --
module example.com/foo

go 1.20

-- a/go.alt.mod --
module example.com/foo

go 1.20

-- overlay-and-dash-modfile/p.go --
package module
-- overlay-and-dash-modfile/go.mod --
-- overlay-and-dash-modfile/overlay.json --
{
	"Replace": {
		"alternate.mod": "../../../overlay/overlay-and-dash-modfile-alternate-mod"
	}
}
-- $WORK/overlay/overlay-and-dash-modfile-alternate-mod --
module found.the/module
-- carve/go.mod --
module carve
-- carve/overlay_carve_module.json --
{

			Deprecated: modFile.Module.Deprecated,
		}
	}
	if modFile.Go != nil {
		f.Go = modFile.Go.Version
	}
	if modFile.Toolchain != nil {
		f.Toolchain = modFile.Toolchain.Name
	}
	for _, r := range modFile.Require {
		f.Require = append(f.Require, requireJSON{Path: r.Mod.Path, Version: r.Mod.Version, Indirect: r.Indirect})
	}
	for _, x := range modFile.Exclude {
		f.Exclude = append(f.Exclude, x.Mod)
	}

add and drop a use directive from the go.work file's set of module directories.

The -replace=old[@v]=new[@v] flag adds a replacement of the given
module path and version pair. If the @v in old@v is omitted, a
replacement without a version on the left side is added, which applies
to all versions of the old module path. If the @v in new@v is omitted,
the new path should be a local module root directory, not a module

# list excluded version
go list -modfile=go.exclude.mod -m rsc.io/quote@v1.5.0
stdout '^rsc.io/quote v1.5.0$'

# list versions should not print excluded versions
go list -m -versions rsc.io/quote
stdout '\bv1.5.0\b'
go list -modfile=go.exclude.mod -m -versions rsc.io/quote
! stdout '\bv1.5.0\b'

# list query with excluded version
go list -m rsc.io/quote@>=v1.5
stdout '^rsc.io/quote v1.5.0$'
go list -modfile=go.exclude.mod -m rsc.io/quote@>=v1.5

cd $GOROOT/src
env GOFLAGS=
env GOWORK=off
go doc cryptobyte
stdout '// import "golang.org/x/crypto/cryptobyte"'

cd $GOROOT/src/cmd/go
go doc modfile
stdout '// import "golang.org/x/mod/modfile"'

# When outside of the 'std' module, its vendored packages
# remain accessible using the 'vendor/' prefix, but report
# the correct "// import" comment as used within std.
cd $GOPATH

func checkVendorConsistency(indexes []*modFileIndex, modFiles []*modfile.File, modRoots []string) {
	// readVendorList only needs the main module to get the directory
	// the vendor directory is in.
	readVendorList(VendorDir())

	if len(modFiles) < 1 {
		// We should never get here if there are zero modfiles. Either
		// we're in single module mode and there's a single module, or

# Recursive go commands started with 'go generate' should not get an explicitly
# passed -modfile, but they should see arguments from GOFLAGS.
cp go.alt.mod go.gen.mod
env OLD_GOFLAGS=$GOFLAGS
env GOFLAGS=-modfile=go.gen.mod
go generate -modfile=go.alt.mod .
env GOFLAGS=$OLD_GOFLAGS
grep example.com/exclude go.gen.mod
! grep example.com/exclude go.alt.mod