SolutionDir set to *Undefined* in post-build xcopy event

I just ran into the same problem with TeamCity.

The issue here is the $(SolutionDir) property in your build file. You haven't defined it in your call to MsBuild (this is why you see the word undefined in your output).

Call msbuild with the property set, like this:

msbuild myproject.csproj /property:SolutionDir="solution directory"\

Where "solution directory" is the directory containing your solution file. Note the trailing slash, you'll need that to make sure the path is correctly formed.

I fixed this for problems with the Microsoft.SqlServer.Compact nuget package (which adds a similar post-build script), by adding:

<SolutionDir Condition="'$(SolutionDir)'=='' or '$(SolutionDir)'=='*Undefined*'">..\</SolutionDir>

right above the <PostBuildEvent>. You'll want to adjust the relative path to match your project layout.