title: VSO Build definition to retrieve code from multiple repositories and multi-step build and reference
body: <p>We have a single Team Project in Visual Studio Online that makes use of multiple repos maintained by different development teams.</p>
  
  <pre><code>E.g.
  Common repo - common framework, libraries
  App1 repo - First application
  App2 repo - Second application
  </code></pre>
  
  <p>Primary Desire</p>
  
  <p>App1, App2 teams depend on the Common projects/assemblies for base functionality. We found that configuring Build definitions for VSO (within Visual Studio 2013) that it seems focused only on a single Git repository.</p>
  
  <p>How is it possible to pull code sources from multiple repositories to perform a composite build? Compile the common projects, make assemblies available for reference by the dependent app projects, etc. Or even possibly pull out a specific version (tag) from the Common repo which dependents should be working on.</p>
  
  <p>For now we kind of have explicitly pre-compiled and package the common assemblies into specific versions, which the dependent solutions then include as a fixed binary library asset within their own repositories.</p>
  
  <p>Advanced Desire</p>
  
  <p>The apps are in reality sub-systems to a grander system. How is it possible to have a single Build definition build the code from all these different repositories in a unified sequence?</p>