Evaluate rounding error in Go lang

rounding.go

// It diverges 4611686022000000000 -1.024000e+03
package main

import "fmt"

const gigaInt = 1000000000
const gigaExp = 1e9

func main() {
	var i = uint64(0)
	var e = float64(0.0)
	var err = float64(0.0)
	for err == 0.0 {
		i += gigaInt
		e += gigaExp
		err = e - float64(i)
	}
	fmt.Printf("%d %e\n", i, err)
}