Overriding ToolsVersion Settings

You can change the Toolset for projects and solutions in one of three ways:

1. by using the /ToolsVersion switch (or /tv, for short) when you build the project or solution from the command line

2. by setting the ToolsVersion parameter on the MSBuild task

3. by setting the $(ProjectToolsVersion) property on a project within a solution. This lets you build a project in a solution with a Toolset version that differs from that of the other projects.

Override the ToolsVersion Settings of Projects and Solutions on Command Line Builds

Although Visual Studio projects typically build with the ToolsVersion specified in the project file, you can use the /ToolsVersion (or /tv) switch on the command line to override that value and build all of the projects and their project-to-project dependencies with a different Toolset. For example:

msbuild.exe someproj.proj /tv:12.0 /p:Configuration=Debug  

In this example, all projects are built using ToolsVersion 12.0. (However, see the section "Order of Precedence" later in this topic.)

When using the /tv switch on the command line, you can optionally use the $(ProjectToolsVersion) property in individual projects to build them with a different ToolsVersion value than the other projects in the solution.

Override the ToolsVersion Settings Using the ToolsVersion Parameter of the MSBuild Task

The MSBuild task is the primary means for one project to build another. To enable the MSBuild task to build a project with a different ToolsVersion than the one specified in the project, it provides an optional task parameter named ToolsVersion. The following example demonstrates how to use this parameter:

1. Create a file that's named projectA.proj and that contains the following code:

   <Project xmlns="https://schemas.microsoft.com/developer/msbuild/2003"  
   ToolsVersion="12.0">  
   
       <Target Name="go" >   
           <Message Text="projectA.proj" />  
           <Message Text="MSBuildToolsVersion: $(MSBuildToolsVersion)" />  
           <Message Text="MSBuildToolsPath:    $(MSBuildToolsPath)" />  
   
           <MSBuild Projects="projectB.proj"  
               ToolsVersion="2.0"  
               Targets="go" />  
       </Target>  
   </Project>  
   

2. Create another file that's named projectB.proj and that contains the following code:

   <Project xmlns="https://schemas.microsoft.com/developer/msbuild/2003"  
   ToolsVersion="12.0">  
   
       <Target Name="go">  
           <Message Text="projectB.proj" />  
           <Message Text="MSBuildToolsVersion: $(MSBuildToolsVersion)" />  
           <Message Text="MSBuildToolsPath:    $(MSBuildToolsPath)" />  
       </Target>  
   </Project>  
   

3. Enter the following command at a command prompt:

   msbuild projectA.proj /t:go /toolsversion:3.5  
   

4. The following output appears. For projectA, the /toolsversion:3.5 setting on the command line overrides the ToolsVersion=12.0 setting in the Project tag.

   ProjectB is called by a task in projectA. That task has ToolsVersion=2.0, which overrides the other ToolsVersion settings for projectB.

   Output:  
     projectA.proj  
     MSBuildToolsVersion: 3.5  
     MSBuildToolsPath:    C:\Windows\Microsoft.NET\Framework\v3.5  
   
     projectB.proj  
     MSBuildToolsVersion: 2.0  
     MSBuildToolsPath:    C:\Windows\Microsoft.NET\Framework\v2.0.50727  
   

Order of Precedence

The order of precedence, from highest to lowest, used to determine the ToolsVersion is:

1. The ToolsVersion attribute on the MSBuild task used to build the project, if any.

2. The /toolsversion (or /tv) switch that's used in the msbuild.exe command, if any.

3. If the environment variable MSBUILDTREATALLTOOLSVERSIONSASCURRENT is set, then use the current ToolsVersion.

4. If the environment variable MSBUILDTREATHIGHERTOOLSVERSIONASCURRENT is set and the ToolsVersion defined in the project file is greater than the current ToolsVersion, use the current ToolsVersion.

5. If the environment variable MSBUILDLEGACYDEFAULTTOOLSVERSION is set, or if ToolsVersion is not set, then the following steps are used:

   1. The ToolsVersion attribute of the Project element of the project file. If this attribute doesn’t exist, it is assumed to be the current version.

   2. The default tools version in the MSBuild.exe.config file.

   3. The default tools version in the registry. For more information, see Standard and Custom Toolset Configurations.

6. If the environment variable MSBUILDLEGACYDEFAULTTOOLSVERSION is not set, then the following steps are used:

   1. If the environment variable MSBUILDDEFAULTTOOLSVERSION is set to a ToolsVersion that exists, use it.

   2. If DefaultOverrideToolsVersion is set in MSBuild.exe.config, use it.

   3. If DefaultOverrideToolsVersion is set in the registry, use it.

   4. Otherwise, use the current ToolsVersion.

See Also

Multitargeting
MSBuild Concepts
Toolset (ToolsVersion)
Standard and Custom Toolset Configurations