I believe the problem is documented &lt;strike&gt;[here][1]&lt;/strike&gt; [moved here][2] and looks like it might be a bug in visual studio, but I&#39;m wondering if anyone knows of a workaround.

Basically I have the following two lines (among other things) one right after the other in the prebuild event. 

    &quot;C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe&quot; /p:configuration=Release;platform=x86 /t:rebuild &quot;$(SolutionDir)Folder1\Project1.csproj&quot;
    
    &quot;C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe&quot; /p:configuration=Release;platform=x86 /t:rebuild &quot;$(SolutionDir)Folder2\Folder3\Project2.csproj&quot; 

The first one succeeds and the other fails saying that `The command &quot;&quot;C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe&quot; /p:configuration=Release;platform=x86 /t:rebuild  &quot;*Undefined*Folder2\Folder3\Project2.csproj&quot;&quot; exited with code 1.`.

**Edit:**  
Figured out the problem was that one of the other projects with the same line as it&#39;s prebuild failed, since MSBuild itself doesn&#39;t know about the macros.


  [1]: https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=419262
[2]: https://developercommunity.visualstudio.com/content/problem/65435/solutiondir-macro-at-build-event-gives-undefined-w.html

All Prebuild Solutions on Gang of Coders

Total of 1 Prebuild Solutions

Prebuild event in Visual Studio replacing $(SolutionDir) with Undefined

All Prebuild Solutions on Gang of Coders

Total of 1 Prebuild Solutions

Prebuild event in Visual Studio replacing $(SolutionDir) with *Undefined*

Prebuild event in Visual Studio replacing $(SolutionDir) with Undefined