title: Building Autofac from sources
body: <p>How to build Autofac from sources? I found only one deprecated wiki page.</p>
  
  <p>I've tried to launch go.cmd (.NET Framework 4.0), but it failed with errors:</p>
  
  <pre><code>    C:\Autofac\Autofac.csproj" (default target) (4) -&gt;
      (CoreCompile target) -&gt;
      Builder\MetadataConfiguration.cs(28,14): error CS0234: The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?)
      [C:\Autofac\Core\Source\Autofac\Autofac.csproj] Features\LazyDependencies\LazyWithMetadataRegistrationSource.cs(28,14): error CS0234: The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?) 
  </code></pre>
  
  <p>What I am doing wrong?</p>