title: 'Additional include directories' in visual studio 2010 doesn't work
body: <p>I am banging my head on this one for a while so I figure I will post. I have two library projects where Project2 uses/references Project1 in the following directory structure.</p>
  
  <pre><code>c:\code\Library\Project1
  c:\code\Library\Project2
  </code></pre>
  
  <p>Both are library projects. I have included the path in Project2 at Properties>Configuration Properties>C/C++>General>'Additonal Include Directories'. It reads <code>..\Project1; %(AdditionalIncludeDirectories)</code></p>
  
  <p>Now there is a file in Project2 which #includes file that is present in project1 folder. Inspite of having included the path as above it still comes up with an error:</p>
  
  <pre><code>1&gt;c:\code\Library\Project2\MyTestDlg.cpp(6): fatal error C1083: Cannot open include file: 'GraphCtrl.h': No such file or directory
  </code></pre>
  
  <p>The weird thing is that similar setting works if I don't change the original project names. The projects are originally in folder where they link fine.</p>
  
  <pre><code>c:\code\Library\Project1 1.0.0
  c:\code\Library\Project2 1.0.0
  </code></pre>
  
  <p>What I am doing is removing the last version names from the project folders (and relink them together again) but this has become a nightmare! Any suggestions?</p>
  
  <p>p.s I did research on this quite a bit and it seems like has to do with length of the directories but I think I am well with in limits. The fact that previously longer folder names work and short doesn't, it shows lengths are not the issue.</p>
  
  <p>Addon:</p>
  
  <p>The following is the actual error I am getting with actual file names: One of the problem is that somehow it still references the old library with full name <code>GraphCtrlLib 1.0.0.0</code> even though I have completely removed it and can't find any more reference of it. I this it probably is not related to this error though.</p>
  
  <pre><code>1&gt;Build started 12/11/2012 5:16:02 PM.
  1&gt;C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.Targets(1200,9): warning : The referenced project '..\Graph\Graph.vcxproj' does not exist.
  1&gt;InitializeBuildStatus:
  1&gt;  Touching "Debug\ViewerLib.unsuccessfulbuild".
  1&gt;ClCompile:
  1&gt;  All outputs are up-to-date.
  1&gt;  OpenViewerDlg.cpp
  1&gt;c:\code\libraries\viewerlib\viewerdlg.cpp(6): fatal error C1083: Cannot open include file: 'GraphCtrl.h': No such file or directory
  </code></pre>