In the "main" branch, our setup authoring (in files.swr) installs a couple of our .props and .targets files to "<VS install>\MSBuild\Microsoft\NuGet\16.0". This is the wrong path, as other MSBuild files try to import those .props and .targets files from "<VS install>\MSBuild\Microsoft\NuGet\<VS major version>.0". As a result these files won't be imported, and non-SDK-style projects attempting to use PackageReference-style NuGet will be very broken. Specifically, they won't read the project.assets.json file and so most reference information will be missing.
The fix here is to stop hard-coding the VS major version in file.swr and instead compute the value from a single source.
1. In Versions.props we split `VersionPrefix` into `MajorVersion` and `MinorVersion` properties.
2. In Microsoft.NuGet.Build.Tasks.Setup.csproj we expose `MajorVersion` to files.swr by creating a `SwrProperty` item of the same name.
3. In files.swr we consume this new `MajorVersion` property.
Now, when we update the major version in Versions.props the setup authoring will be updated as well.
haileymck
Michael Yanni
Tom Meschter
Tom Meschter
Daniel Monroy