VCBuild task in MSBuild - change outputpath

I'm attempting to write an automated build for one of our products, and I've hit up against a wall for some of our VC++ projects: I need to be able to set the output path to where the assemblies will be copied once its done.

Here is a makeshift msbuild file:

<Project DefaultTargets="Build"
         xmlns="http://schemas.microsoft.com/developer/msbuild/2003"
         ToolsVersion="3.5">
 <Target Name="Build">
   <VCBuild Projects="C:\src\SomeProject\SomeProject.vcproj"
            ToolPath="C:\Program Files\Microsoft Visual Studio 9.0\VC\vcpackages"
            Configuration="Debug" />
 </Target>
</Project>

Stijn's Answer:

I thought I'd use this space to clarify how I personally used Stijn's answer to solve this. He has some code in his MSBuild file that writes the vsprops file for him. I decided to take a simpler approach and just write the file manually.

I created this file, called build.vsprops (my output path is V:)

<?xml version="1.0"?>
<VisualStudioPropertySheet ProjectType="Visual C++"
                           Version="8.00"
                           Name="Overrides"
                           OutputDirectory="V:\">
  <Tool Name="VCCLCompilerTool"
        AdditionalUsingDirectories="V:\" />
</VisualStudioPropertySheet>

Then I edited my MSBuild file to add the Override parameter:

<Project DefaultTargets="Build"
         xmlns="http://schemas.microsoft.com/developer/msbuild/2003"
         ToolsVersion="3.5">
 <Target Name="Build">
   <VCBuild Projects="C:\src\SomeProject\SomeProject.vcproj"
            ToolPath="C:\Program Files\Microsoft Visual Studio 9.0\VC\vcpackages"
            Configuration="Debug"
            Override="$(MSBuildProjectDirectory)\build.vsprops" />
 </Target>
</Project>

Solution

have a look at the Override parameter for the VCBuild task. Basically you specify a property sheet which you can use to override whatever property you want (it has the same effect as adding a property sheet to the top of the list in a project within VS). You could even generate the override file using the WriteLinesToFile task.

Example:

<PropertyGroup>
  <VCOverridesFile Condition=" '$(VCOverridesFile)'=='' ">overrides.vsprops</VCOverridesFile>
  <VCOverridesOpen>%3C?xml version=%221.0%22?%3E%0D%0A%3CVisualStudioPropertySheet ProjectType=%22Visual C++%22 Version=%228.00%22 Name=%22My Overrides%22%3E</VCOverridesOpen>
  <VCOverridesClose>%3C/VisualStudioPropertySheet%3E</VCOverridesClose>
  <MyOutPath>&lt;Tool Name="VCLinkerTool" OutputFile ="c:\my.exe"/&gt;</MyOutPath>
</PropertyGroup>

<Target Name="WriteOverridesFile">
  <WriteLinesToFile
    File="$(VCOverridesFile)"
    Lines="$(VCOverridesOpen);$(AdditionalVCOverrides);$(VCOverridesClose)"
    Overwrite="true" />
</Target>

Then pass $(VCOverridesFile) to the Override property and make sure your VCBuild Task DependsOnTarget WriteOverridesFile.