title: How to stop Visual Studio 2015 expanding environment variables in solution file
body: <p>We make extensive use of environment variables in our C++ solutions in order to specify paths to project files. The form of the path is like: %CODE_BRANCH%\theProject.vcxproj. </p>
  
  <p>The problem is that whenever the solution file is edited - say to add a project - any existing paths are automatically rewritten as relative paths, removing the use of the environment variable. The original path becomes something like ....\Code\9.0\theProject.vcxproj, for example. The developer must then manually edit the file to restore the use of the environment variable. For solutions containing many projects, this gets to be a pain; it's also a diff that's easily overlooked when submitting changes, since superficially it looks reasonable.</p>
  
  <p>Does anyone know a way to prevent VS from modifying the paths?</p>