MSBuild.OutputPathExtension

This MSBuild extension allows changing the output paths when building a solution or a project using Visual Studio or the command line. It replaces the default relative directories Obj and Bin with user-defined paths at build time, without changing the project files. This is designed to be used for speeding up the build process by using a different drive for MSBuild output, i.e. a RAM drive.

How it works

The extension sets well-known properties such as IntermediateOutputPath and OutputPath. If these paths are relative (which is by default) then they are updated to begin with a user-defined path known as the root output path, followed by the drive where the project directory is located and the unrooted full path of the project directory. I.e. given the project directory is E:\Path\To\Projects\MyProject and the build configuration is Debug, then:

• the intermediate path will be set to $(RootOutputPath)\E\Path\To\Projects\MyProject\obj\Debug
• the final output path will be set to $(RootOutputPath)\E\Path\To\Projects\MyProject\bin\Debug

Features

Configure the root output path

The root output path can be configured in two ways:

• by setting the environment variable MSBuildRootOutputPath, which is the preferred way when using the IDE
• by setting the MSBuild property RootOutputPath Note: the root output path does not have effect for user-defined output paths (intermediate and/or final) that are not relative.

Change build behavior when the root output path is not available at build time

The MSBuild property FailIfRootOutputPathNotAvailable can be set to true in order to fail the build in this case. When the property is set to false, the build will issue a warning and it will proceed using the default output paths.

Use links in output path

The MSBuild property UseLinksInOutputPath can be set to true to create symbolic links in the output path. This is used to minimize the disk space used by the project output. Creating symbolic links require SeCreateSymbolicLinkPrivilege. If this is not available at build time then a warning is issued to indicate the process needs to be elevated.

Note: when the project's output type is .exe, the produced .exe is copied as a new file regardless if the property is set or not. This is designed to prevent the various issues that may appear at runtime because of the symbolic link behavior.

Installation

The extension can be installed and uninstalled using PowerShell scripts available in the Setup directory. When installed, the extension is automatically imported by MSBuild via Microsoft.Common.Props and Microsoft.Common.Targets.

MSBuild support

• The extension is supported in MSBuild 15.x, 16.x.
• .NET Core projects are not supported.