Salesforce Marketing Cloud constructor-from-closure bug

a-repro.js

function newEnv () {
  function Foo () {
    Write('Hello World');
  };

  var f = {
    Foo: Foo
  }
  
  return f;
}

var env = newEnv();
var foo = new env.Foo(); // Fails with "env.Foo is not a Type"

b-workaround.js

function newEnv () {
  function Foo () {
    Write('Hello World');
  };

  var f = {
    Foo: Foo
  }
  
  return f;
}

var env = newEnv();
var Foo = env.Foo; // Assign to a new variable
var foo = new Foo();