# We want the upgraded toolchain to match the garble binary
# which we will exec below, as otherwise garble will complain.
# Tell GOTOOLCHAIN to upgrade to the same version thanks to `go mod init`
# setting up a `go` directive with its Go version.
cd mod
go mod init test
exec cat go.mod
cd ..
go env GOVERSION
setenvfile GOVERSION_UPGRADE stdout

# To test that garble works with transparent upgrades via GOTOOLCHAIN,
# use a relatively old version, but still new enough to support GOTOOLCHAIN.
env GOVERSION_BASE=go1.23.0
setup-go ${GOVERSION_BASE}

# We want to use the real GOPROXY so that we can download the newer
# toolchain, and we use the host's GOMODCACHE so we can reuse it.
env GOPROXY=proxy.golang.org
env GOMODCACHE=${HOST_GOMODCACHE}

# Verify that we are using an older version of Go.
exec go version
stdout 'go version '${GOVERSION_BASE@R}

# The builds inside the module use the upgraded toolchain.
cd mod

exec go run .
stderr 'hello from '${GOVERSION_UPGRADE@R}

# Note that garble hides runtime.Version by design, but we know that it requires
# the Go toolchain version to match the exact same version that built garble,
# and that version is most likely newer than GOVERSION_BASE.
exec garble run .
stderr 'hello from unknown'

-- mod/main.go --
package main

import "runtime"

func main() {
	println("hello from", runtime.Version())
}