Chrome Canary eats your stack due to tail call optimization http://www.2ality.com/2015/06/tail-call-optimization.html

index.js

(function () {
"use strict"

const a = () => '' + b() 
const b = () => c()
const c = () => d()
const d = () => new Error().stack

console.log(a())
})()

/*
Error
  at d (<anonymous>:7:17)
  at a (<anonymous>:4:22)
  at <anonymous>:9:13
  at <anonymous>:10:3
*/