Using MSBuild to Build Multiple Configurations

Question

I'm trying to edit my project file to enable me to have a project that builds multiple build configs at once. I've done this using a batching approach and using the MSBuild task (see below).

If I run the script, I get an this error:

Error 103 The OutputPath property is not set for project "ThisMSBuildProjectFile.csproj". Please check to make sure that you have specified a valid combination of Configuration and Platform for this project. Configuration='Debug' Platform='AnyCPU'.

I get this if I add or omit the OutputPath from the MSBuild task. If used the VS2010 debugger to step through the script and the MSBuild Task is called - the debugger steps into the file again and then steps into OutputPath, so afaik, it should pick that value up, no?

Any help for this would be greatly appreciated - it's driving me crazy. Thanks, Paul.

ThisMSBuildProjectFile.csproj (surplus stuff taken out):

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">

  <!-- Only Import normal targets if not building multiple projects -->
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" Condition="'$(Configuration)|$(Platform)' != 'AllBuild|AnyCPU' "/>

  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == '' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>C:\Folder\Etc\Output\$(Configuration)\</OutputPath>
    <OutDir>C:\Folder\Etc\Output\$(Configuration)\</OutDir>
    <BaseOutputPath>C:\Folder\Etc\Output\$(Configuration)\</BaseOutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>

  <!-- Common -->
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <Platform>AnyCPU</Platform>
    <!-- Repeated properties from above here (including, of course, OutputPath) -->  
   </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <!-- Repeated properties from above here (including, of course, OutputPath) --> 
  </PropertyGroup>

  <ItemGroup>
    <Projects Include="C:\Folder\Etc\ThisMSBuildProjectFile.csproj" />
  </ItemGroup>

   <!-- Call this project file again, but with a different configuration - if this was working, this would call multiple  build configs -->
  <Target Name="Build" Condition="'$(Configuration)|$(Platform)' == 'AllBuild|AnyCPU' ">
    <Message Text="hm!"/>
    <!-- Tried thiswith and without the OutputPath property - makes no difference. -->
   <MSBuild  Projects="@(Projects)" Properties="Configuration=Debug;OutputPath=C:\Folder\Etc\Output\" ToolsVersion="4.0" Condition="'$(Configuration)|$(Platform)' == 'AllBuild|AnyCPU' "/>
 </Target>

   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'AllBuild|AnyCPU' ">
    <!-- Repeated properties from above here (including, of course, OutputPath) --> 
  </PropertyGroup>

  <!-- Project files -->
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Core" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Properties\AssemblyInfo.cs" />
    <Compile Include="Blah\Blah.cs" />
  </ItemGroup>

Gangling

Answer 1

It is important to realize that when you use a "MSBuild" task, a new child MSBuild process will be started. The implication of this is that any items and properties you define in the parent MSBuild process will not be automatically passed to/visible from the child MSBuild process unless you explicitely pass them via Properties attribute on MSBuild element (as in <MSbuild Properties="..." />).

To answer your question, I wrote the following self-contained example that runs a child MSBuild project for all the specified configurations:

1. First, create a directory for your MSBuild experiment (for example I used C:\temp\msbuildtest)

2. In this directory, create the first file, main.proj:

   <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build" ToolsVersion="4.0">
       <ItemGroup>
           <ConfigList Condition=" '@(ConfigList)' == '' and $(Config) != '' " Include="$(Config.Split('+'))" /><!-- parse all requested configurations into a list -->
           <ConfigList Condition=" '@(ConfigList)' == '' " Include="Debug" /><!-- if no configurations were specified, default to Debug -->
       </ItemGroup>
       <!--
   
       Build the child project for each requested configuration. -->
       <Target Name="Build">
           <MSBuild Projects="$(MSBuildProjectDirectory)\child.proj" Properties="Configuration=%(ConfigList.Identity);OutputPath=$(MSBuildProjectDirectory)\bin\%(ConfigList.Identity)" Targets="Build" />
       </Target>
   </Project>
   

3. In the same directory, create the second file, child.proj (in your case this would be the actual C# project you're trying to build, but because I'm trying to illustrate my point, I am using a simple child project that instead of running C# compiler just prints values of properties :-) )

   <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build" ToolsVersion="4.0">
       <Target Name="Build">
           <Message Text="Building configuration $(Configuration) with output path $(OutputPath)" Importance="High" />
       </Target>
   </Project>
   

4. Now you can run the example. First the default, if you don't explicitly specify configurations to build:

   C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\msbuild main.proj
   > (cut the noise)
   > Build:
   >   Building configuration Debug with output path C:\temp_c\d\bin\Debug
   

   And then explicitly specified multiple configurations:

   C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\msbuild main.proj /property:Config=Debug+Release+Staging+Production
   > (cut the noise)
   > Build:
   >   Building configuration Debug with output path C:\temp_c\d\bin\Debug
   > Build:
   >   Building configuration Release with output path C:\temp_c\d\bin\Release
   > Build:
   >   Building configuration Staging with output path C:\temp_c\d\bin\Staging
   > Build:
   >   Building configuration Production with output path C:\temp_c\d\bin\Production
   

You should be able to adapt this technique to your situation.

Prospect

Excellent, thank you for this - it's not exactly what I was looking for (as I was looking to minimise the changes to the standard CSProj files), but it's looking like I was over-thinking things. I'll go with this approach for now. Thanks – Gangling

Fyi, this technique is called "Task Batching". There are many ways to do batching and Sayed Ibrahim Hashimi covers them in his book "Inside the Microsoft Build Engine: Using MSBuild and Team Foundation Build" – Naucratis

"It is important to realize that when you use an "MSBuild" task, a new child MSBuild process will be started." This is not true. According to msdn.microsoft.com/en-us/library/z7f65y0d.aspx: "Unlike using the Exec Task to start MSBuild.exe, this task uses the same MSBuild process to build the child projects." This matches my own experience as well. – Deflation

@MilianGardian is there a difference between "And" and "and"? – Mariko

@Mariko I think logical operators are case-insensitive, but I've never tried uppercase variants :-). – Prospect

Answer 2

Something is amiss in your project file. Consider this XML:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == '' ">
  <DebugType>pdbonly</DebugType>
  <Optimize>true</Optimize>
  <OutputPath>C:\Folder\Etc\Output\$(Configuration)\</OutputPath> 
  ...
</PropertyGroup>

Those properties can never be set, since even if $(Configuration) and $(Platform) are empty, they can never match the empty string when concatenated with the bar character; the minimal value for that condition is '|' and not ''. Even if corrected by making the condition compare with '|', you then go on to try to use $(Configuration) in the OutputPath in that PropertyGroup, but $(Configuration) will never have a value at the point it is used. Likewise, where you try to set $(Platform) to 'AnyCPU' it must already have that value. You probably meant to omit the condition on the first PropertyGroup altogether, and you may need to supply default values for $(Configuration) and $(Platform) in an early PropertyGroup with no conditions as well. Diff your whole project against a new project and see if there are any other oddities like this present.

Also notice that on your override of the "Build" target, you have a redundant Condition on the MSBuild task; with the same condition is on the <Target> you don't need it on any of the tasks.

Dian

Sure, the reason that is there is that it's from the standard CSProj file - and the reason it's there is as a fallback if no config is specified. I realise that it wouldn't be hit in the example I gave, but when using the MSBuild debugger, the other conditional groups were hit as expected. Thanks for pointing out the duplication on the child nodes! – Gangling

Perhaps you're missing my point, it isn't a fallback at all, the way it is coded the condition will never evaluate to true, because the left hand side will always contain at least a '|' and the right hand side will always be empty they can never be equal. – Dian

Answer 3

I am not quite sure if I'd wanna go through such a convoluted configuration of the project's csproj file itself. I'd rather setup a separate MSBuild "BuildBoth.proj" file that has a specific target called "Both" that builds the solution in both configurations.

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Both">

    <!-- Calls twice for both configs -->
    <Target Name="Both">
        <MSBuild Projects="buildboth.sln" Targets="Rebuild" Properties="Configuration=Debug"
                         StopOnFirstFailure="true">
        </MSBuild>

        <MSBuild Projects="buildboth.sln" Targets="Rebuild" Properties="Configuration=Release"
                         StopOnFirstFailure="true">
        </MSBuild>
    </Target>

    <!-- single config targets

    <Target Name="Debug">
        <MSBuild Projects="buildboth.sln" Targets="Rebuild" Properties="Configuration=Debug"
                         StopOnFirstFailure="true">
        </MSBuild>
    </Target>

    <Target Name="Release">
        <MSBuild Projects="buildboth.sln" Targets="Rebuild" Properties="Configuration=Release"
                         StopOnFirstFailure="true">
        </MSBuild>
    </Target>
    -->

</Project>

Then I'd run the command (verbosity set Minimal) to target Both

C:\Projects\experiments\BuildBoth>msbuild /v:m /target:Both BuildBoth.proj
Microsoft (R) Build Engine Version 4.0.30319.1
[Microsoft .NET Framework, Version 4.0.30319.225]
Copyright (C) Microsoft Corporation 2007. All rights reserved.

  BothWpf -> C:\Projects\experiments\BuildBoth\BothWpf\bin\Debug\BothWpf.exe
  BothWpf -> C:\Projects\experiments\BuildBoth\BothWpf\bin\Release\BothWpf.exe

Harrar

Hi - thanks, I realise I can have a standalone project, but the idea was for members of the team to all be able to push builds from VS rather than shelling out - I was looking to minimally alter the standard CSProj file to enable the rest of the team to do this. Thaks for replying though. – Gangling