<msbuild> task or msbuild.exe with NAnt?

The NAntContrib assumes .NET Framework V2.0. If you want to use .NET 3.5, you'll need to call MsBuild.exe directly. As you upgrade to new versions of .NET, you need only modify the MSBuildPath property.

Here's an example:

<property name="MSBuildPath" value="C:\WINDOWS\Microsoft.NET\Framework\v3.5\MSBuild.exe"/>    
<target name="build">
    <exec program="${MSBuildPath}">
        <arg line='"${SolutionFile}"' />
        <arg line="/property:Configuration=${SolutionConfiguration}" />
        <arg value="/target:Rebuild" />
        <arg value="/verbosity:normal" />
        <arg value="/nologo" />
        <arg line='/logger:"C:\Program Files\CruiseControl.NET\server\ThoughtWorks.CruiseControl.MsBuild.dll"'/>
    </exec>
</target>

The value MSBuildPath for different versions of .NET are

• 2.0, 3.0 C:\Windows\Microsoft.NET\Framework64\v2.0.50727\MSBuild.exe
• 3.5 C:\Windows\Microsoft.NET\Framework64\v3.5\MSBuild.exe
• 4, 4.5.x, 4.6.x, 4.7.x C:\Windows\Microsoft.NET\Framework64\v4.0.30319\MSBuild.exe

For a 32-bit build, change Framework64 to Framework

Update Following up on some of the comments, the value attribute is used for parameters that have no white space characters where as line is used for parameters that contain white spaces. Otherwise, the NAnt would use the space as an end of input.

Here is a simple target

    <target>

    <loadtasks assembly="${nant::get-base-directory()}/../../nantcontrib-0.85/bin/NAnt.Contrib.Tasks.dll" />

    <msbuild project="${filepath.root}/yourproject.csproj" verbose="true">     
          <arg value="/p:Platform=${build.platform}" />
          <arg value="/t:Rebuild" />
          <arg value="/p:OutputPath=${build.dir}/bin/" />
        </msbuild>

 </target>