func SetReporter(thread *starlark.Thread, r Reporter) {
	thread.SetLocal(localKey, r)
}
SetReporter associates an error reporter (such as a testing.T in
a Go test) with the Starlark thread so that Starlark programs may
report errors to it.
package starlarktest  
import (
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"sync"
	"go.starlark.net/starlark"
	"go.starlark.net/starlarkstruct"
)
const localKey = "Reporter"
type Reporter interface {
	Error(args ...interface{})
}