Changing a pin inside a setInterval causes Espruino to hang

When I try to change a pin's mode inside a setInterval after a number of loops Espruino hangs.
For example:

var count = 0;

const onInit = () => {
  var loop = setInterval(() => {
    if (count === 1000) {
      digitalWrite(1, 0);
    }
    console.log('foo', count);
    count = count + 1;
  }, 5);
  
  setTimeout(function() {
    clearInterval(loop);
    console.log("foobar");
  }, 10000);
};

setTimeout(onInit, 1000);

It will turn the pin off and log foo 999. It will never log foobar.

The odd thing is that I can create a blink loop with setInterval like this:

var state = 0;

const onInit = () => {
  var loop = setInterval(() => {
    digitalWrite(1, state);
    console.log('foo', state);
    state = !state;
  }, 500);
};

setTimeout(onInit, 1000);

Any help would be great!