I'm having the same issue with RepositoryPath ignored during build. Using NuGet 2.5.40416.9020
Right-click on any project > Build. NuGet installs everything into the default "packages" folder regardless of "RepositoryPath" setting in NuGet.config
Right-click on any project > Build. NuGet installs everything into the default "packages" folder regardless of "RepositoryPath" setting in NuGet.config