Running file-based app using repo-local dotnet install performs restore for .proj file in root of repo

[DamianEdwards]

When using a repo-local install of the dotnet CLI, e.g. like that in the dotnet/runtime repo, attempting to run a file-based app using an absolute path to a completely different location from the repo results in the project file in the repo being restored.

Repro:

1. Clone https://github.com/dotnet/runtime
2. In the repo root, run dotnet.cmd or dotnet.sh to install the repo-local copy of the dotnet CLI
3. Create a directory in the drive root like scripts and put a hello world file-based app in it named hello.cs
4. From the repo root, run .\.dotnet\dotnet run D:\scripts\hello.cs (or simply dotnet run D:\scripts\hello.cs)
5. Note that restore runs for projects in the repo (likely from the Build.proj in the repo root)

[jjonescz]

This is currently by design. Whenever there is a project file in the current directory, dotnet run fallbacks to its project-based behavior to avoid a breaking change. In your example, dotnet run D:\scripts\hello.cs would always run the Build.proj with command-line arguments D:\scripts\hello.cs passed to the built app, so we preserve that behavior.

That being said we should probably avoid this fallback at least if you do dotnet D:\scripts\hello.cs (without the run verb) because we don't need any backwards compatibility there.