title: System.MissingMethodException when using certain methods from FSharp PowerPack and compiling to a Class Library
body: <p>So I'm just getting started with F#, and I'm encountering a very weird issue where I get a System.MissingMethodException thrown when using certain methods from the FSharp PowerPack.</p>
  
  <p>This does not happen for all methods in the same module. It also does not happen if I compile my assembly as an Application instead of a class library.</p>
  
  <p>Reproduction steps:</p>
  
  <ol>
  <li>Create 2 assemblies, one Class Library and one Application.</li>
  <li>Add nunit.framework and the FSharp.PowerPack DLLs as references to both assemblies.</li>
  <li><p>Create the following test fixture in each assembly.</p>
  
  <pre><code>open NUnit.Framework
  
  [&lt;TestFixture&gt;]
  type Tests() = class
  
      [&lt;Test&gt;]
      member self.OfSeq() =
          // Will always succeed
          Matrix.Generic.ofSeq [[1]] |&gt; ignore
  
      [&lt;Test&gt;]
      member self.OfList() =
          // Will fail under certain conditions with a System.MissingMethodException
          Matrix.Generic.ofList [[1]] |&gt; ignore
  end
  </code></pre></li>
  <li>Compile both assemblies.</li>
  <li>Open each assembly in NUnit and run all the tests.</li>
  </ol>
  
  <p>When I do this the Application runs just fine (all tests pass), but the Class Library fails with the following exception:</p>
  
  <pre><code>System.MissingMethodException : Method not found: 'Microsoft.FSharp.Math.Matrix`1&lt;!!0&gt; Generic.ofList(Microsoft.FSharp.Collections.FSharpList`1&lt;Microsoft.FSharp.Collections.FSharpList`1&lt;!!0&gt;&gt;)'.
     at Temp2.Tests.OfList()
  </code></pre>
  
  <p>What is going on here?</p>
  
  <p>Another method that produces the issue is matrix.PermuteColumns.</p>
  
  <p>Additional Info:</p>
  
  <ul>
  <li>I'm compiling both assemblies for .NET 4.5</li>
  <li>I'm compiling using Visual Studio 2012 RC</li>
  <li>I'm using NUnit version 2.5.10.11092</li>
  <li>I'm using FSharp PowerPack version 2.1.3.1 (though the DLL properties state that it's 2.0.0)</li>
  </ul>
  
  <p>Let me know if there's additional information that would be of use.</p>