The new NuGet uses tolower paths, and we need to react to it. Port https://github.com/dotnet/cli/pull/2722 Port https://github.com/dotnet/cli/pull/3554
PR #2493 introduced the new project.json schema. The tree has 118 files with the old schema, which added several hundred warnings. This change can't go in until PR #2864 does - it relies on those bug fixes.