Unsupported protocol message for clojure

[je...@altometrics.com]

I'm having problems using the [clojure] protocol in my Drakefile. Whenever I try to use it, I get the message:

drake: unsupported protocol

When I use an obviously wrong protocol, I get a different message:

drake: unknown protocol: clo_du_jour

I have essentially the same problem (though the output varies a little) in a variety of versions, including:

- the HEAD of the `develop` branch
- the HEAD of the `master` branch
- the `v0.1.6` tag
- the `v0.1.5` tag
- the `0.1.2` tag

My rule is pretty simple, so I can't imagine that's a problem:

output.txt <- input.tsv [clojure]
(prn inputs)

Lastly, I'll note that I am able to run [shell] rules without a problem, so Drake is functional for me at some level.

Anybody know what might be going on here? My guess is I'm doing something stupid because the only alternative I see is that Drake's [clojure] protocol has been broken for the past several releases. :-)

Thanks,
-Jeff T.