title: Haskell package versioning policy - changes in dependencies
body: <p>Let's say I have libfoo. It depends on libbar. In accordance with the <a href="http://www.haskell.org/haskellwiki/Package_versioning_policy" rel="noreferrer">Package Versioning Policy</a>, I specify</p>
  
  <pre><code>libbar ==0.1.*
  </code></pre>
  
  <p>in the Build-depends: in my cabal file.</p>
  
  <p>Then the developer of libbar releases a new version, 0.2. I test it and there are no changes that affect libfoo. So I change my Build-depends to</p>
  
  <pre><code>libbar ==0.2.*
  </code></pre>
  
  <p>or perhaps to</p>
  
  <pre><code>libbar &gt;= 0.1 &amp;&amp; &lt; 0.3
  </code></pre>
  
  <p>though I can think of reasons not to do it the latter way. This is the <em>only</em> change I make to libfoo.</p>
  
  <p>libfoo exports functions that accept types defined in libbar and return types defined in libbar. However the change to libbar does not affect any of these functions.</p>
  
  <p>The first version of libfoo is 0.1.0.0. What version number should the second release of libfoo have?</p>