GoVersion string
	Toolchain string // for callers if they want to use it, but not printed
}

func (e *TooNewError) Error() string {
	var explain string
	if Startup.GOTOOLCHAIN != "" && Startup.GOTOOLCHAIN != "auto" {
		explain = "; GOTOOLCHAIN=" + Startup.GOTOOLCHAIN
	}
	if Startup.AutoFile != "" && (Startup.AutoGoVersion != "" || Startup.AutoToolchain != "") {
		explain += fmt.Sprintf("; %s sets ", base.ShortPath(Startup.AutoFile))

env GOTOOLCHAIN=auto
go get -v .
cmp stderr get-v-stderr.want
cmp go.mod go.mod.tidy

cp go.mod.orig go.mod
env GOTOOLCHAIN=local
! go get -u -v .
stderr '^go: example.net/a@v0.2.0: module ./a2 requires go >= 1.22.0 \(running go 1.21.0; GOTOOLCHAIN=local\)$'
env GOTOOLCHAIN=auto
go get -u -v .
cmp stderr get-u-v-stderr.want
cmp go.mod go.mod.upgraded

-- tidy-stderr.want --

grep '^go 1.21$' go.work
! grep toolchain go.work
env GOTOOLCHAIN=local
! go work sync
stderr '^go: cannot load module m1_22_0 listed in go.work file: m1_22_0'${/}'go.mod requires go >= 1.22.0 \(running go 1.21; GOTOOLCHAIN=local\)$'
stderr '^go: cannot load module m1_22_1 listed in go.work file: m1_22_1'${/}'go.mod requires go >= 1.22.1 \(running go 1.21; GOTOOLCHAIN=local\)$'
env GOTOOLCHAIN=auto
go work sync

	}
	return "go" + latest, nil
}

// HasAuto reports whether the GOTOOLCHAIN setting allows "auto" upgrades.
func HasAuto() bool {
	env := cfg.Getenv("GOTOOLCHAIN")
	return env == "auto" || strings.HasSuffix(env, "+auto")
}

// HasPath reports whether the GOTOOLCHAIN setting allows "path" upgrades.
func HasPath() bool {
	env := cfg.Getenv("GOTOOLCHAIN")
	return env == "path" || strings.HasSuffix(env, "+path")

env TESTGO_VERSION=go1.21
env GOTOOLCHAIN=local
! go mod download rsc.io/future@v1.0.0
stderr '^go: rsc.io/future@v1.0.0 requires go >= 1.999 \(running go 1.21; GOTOOLCHAIN=local\)$'

-- go.mod --
module m
go 1.21

-- x.go --
package p

! stderr toolchain # already gone, was not added
grep 'go 1.22.1' go.mod
! grep toolchain go.mod

env TESTGO_VERSION=go1.22.1
env GOTOOLCHAIN=local
! go get go@1.22.3
stderr 'go: updating go.mod requires go >= 1.22.3 \(running go 1.22.1; GOTOOLCHAIN=local\)$'

env TESTGO_VERSION=go1.30
go get toolchain@1.22.3
grep 'toolchain go1.22.3' go.mod

go get go@1.22.1
grep 'go 1.22.1' go.mod
go get m2@v1.0.0

GOPROXY=https://proxy.golang.org,direct
GOSUMDB=sum.golang.org

# Automatically download newer toolchains as directed by go.mod files.
# See https://go.dev/doc/toolchain for details.

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build js || wasip1

package toolchain

import "cmd/go/internal/base"

func execGoToolchain(gotoolchain, dir, exe string) {
	base.Fatalf("execGoToolchain unsupported")

# with --mod=readonly moduleInfo was not setting the GoVersion for the module
# because the checksumOk function was failing because modfetch.GoSumFile
# was not set when running outside of a module.

env GOTOOLCHAIN=local

# Test support for go work edit -toolchain to set toolchain to use

env GOTOOLCHAIN=local
env GO111MODULE=on

! grep toolchain go.work
go work edit -toolchain=go1.9
grep 'toolchain go1.9' go.work

go work edit -toolchain=default
grep 'toolchain default' go.work

go work edit -toolchain=none
! grep toolchain go.work

-- go.work --
go 1.8
use .
-- go.mod --