NoMethodError: undefined method `to_csv' for ["a", "b"]:Array
<p>Why is this new Rails project having a problem finding the <code>to_csv</code> method?</p>

<p>I'm running Ruby v2.1.3, installed with <code>rbenv</code>. There is no reason whatsoever for it not to find this method.</p>

<p>I have another project running v2.1.0 where I make heavy use of <code>to_csv</code> on array objects. No problems there.</p>