title: Depending on a local package in cabal
body: <p>I've written a few packages containing some extra functions for dealing with common types that reflect the way I like to use them (for instance, I prefer to treat Bson documents as maps, rather than lists of fields). I keep these packages in local source directories, not on Hackage.</p>
  
  <p>I would like to introduce dependencies between these packages in their <code>.cabal</code> files, using cabal's <code>build-depends</code> system. But this leads to the following error (<code>bson-docmap</code> being a local module):</p>
  
  <pre><code>cabal: At least the following dependencies are missing:
  bson-docmap &gt;=0.0
  </code></pre>
  
  <p>Is it possible to point cabal to a local directory as an alternate repository?</p>
  
  <p>My current workaround is to keep all my modules in a single local package, but I would prefer to break them apart if possible.</p>