Are you using Ruby 2.0 by any chance?  I suspect it's related to this:  https://github.com/rails/rails/pull/8405

 

We haven't tested in Ruby 2.0 yet (I think it was just released last month).  We will definitely be supporting it, and that particular problem looks like a very easy fix, but the immediate route to getting going is to use ruby 1.9.x.

 

We'll try to get stuff patched in a hurry; thanks for the heads up.  Sorry about the dysentery.

 

-e

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still not tested in 2.0, but this particular issue is fixed.

  --Ethan McCutchen.....2013-04-03 15:26:09 +0000