}

var ErrTooNew = errors.New("module too new")

func (e *TooNewError) Is(err error) bool {
	return err == ErrTooNew
}

// A Switcher provides the ability to switch to a new toolchain in response to TooNewErrors.
// See [cmd/go/internal/toolchain.Switcher] for documentation.
type Switcher interface {
	Error(err error)
	Switch(ctx context.Context)

// to resolve them.
//
// The client calls [Switcher.Error] repeatedly with errors encountered
// and then calls [Switcher.Switch]. If the errors included any
// *gover.TooNewErrors (potentially wrapped) and switching is
// permitted by GOTOOLCHAIN, Switch switches to a new toolchain.
// Otherwise Switch prints all the errors using base.Error.
//
// See https://go.dev/doc/toolchain#switch.