New Post: Nuget 2.5 doesn't add project references as a depedency

According to http://docs.nuget.org/docs/release-notes/nuget-2.5,

If the referenced project has corresponding nuspec file, e.g. there is a file called proj1.nuspec in the same directory as proj1.csproj, then this project is added as a dependency to the package, using the id and version read from the nuspec file.

When I create a solution with two projects, both of which have *.nuspec files with the same name as their *.csproj files, with a dependency from one project to the other, install NuGetPowerTools, enable package build, enable package restore, and build solution, the *.nupkg files are generated, but opening them with package explorer doesn't reveal the dependency. The fallback scenario

Otherwise, the files of the referenced project are bundled into the package. Then projects referenced by this project will be processed using the sames rules recursively.

also doesn't happen.

I'm using nuget 2.5.40416.9020 with VS 2008. How do I enable this?