"fmt"
	"go/build"
	"internal/godebugs"
	"sort"
	"strconv"
	"strings"

	"cmd/go/internal/gover"
	"cmd/go/internal/modload"
)

var ErrNotGoDebug = errors.New("not //go:debug line")

func ParseGoDebug(text string) (key, value string, err error) {
	if !strings.HasPrefix(text, "//go:debug") {
		return "", "", ErrNotGoDebug
	}
	i := strings.IndexAny(text, " \t")
	if i < 0 {