title: Leksah, jump to definition within current package and to names defined in packages installed in Sandbox
body: <p>I'm using Leksah 0.15.0.1 built with ghc 7.10.1. </p>
  
  <p>Here is the problem :</p>
  
  <p>If I ctrl+click on a function name which is from a system wide installed library then Leksah goes to the definition, just fine! </p>
  
  <p><strong>However</strong>, this (go to definition) does not work for </p>
  
  <p>1) functions defined within the currently edited package</p>
  
  <p>2) functions defined in packages that are located in a sandbox. </p>
  
  <p>For example in the picture below, I can jump to the definition of <code>SDL.QuitEvent</code> but not to the definition of <code>AppInput</code>. </p>
  
  <p>Which is strange because <code>AppInput</code> is defined in the same file that I am editing and <code>SDL.QuitEvent</code> is defined in a system wide installed cabal package.</p>
  
  <p>Any idea how to fix this? What might be going wrong ?'</p>
  
  <p><img src="https://i.stack.imgur.com/BQqpW.jpg" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/61Q8h.jpg" alt="enter image description here"></p>