Can no longer use relative pathing

[whodges]

When I run "dnt switch-to-projects" now with my switcher.json as something along the lines of:

{
  "solution": "Solution.sln",
  "mappings": {
    "Project": "../Project/Project.csproj"
  }
}

I get the following error that's caused by my use of relative pathing:

Executing: dotnet
Names cannot:
- contain any of the following characters: / ? : \ * " < > |
- contain control characters
- be system reserved names, including 'CON', 'AUX', 'PRN', 'COM1' or 'LPT2'
- be '.' or '..' (Parameter 'name')
System.InvalidOperationException: Process execution failed: dotnet
   at Dnt.Commands.Infrastructure.ProcessUtilities.ExecuteAsync(String command, String arguments, Boolean verbose, Boolean writeConsole, CancellationToken cancellationToken) in C:\projects\dnt\src\Dnt.Commands\Infrastructure\ProcessUtilities.cs:line 60
   at Dnt.Commands.CommandBase.ExecuteCommandAsync(String command, String arguments, Boolean writeConsole, IConsoleHost host, CancellationToken cancellationToken) in C:\projects\dnt\src\Dnt.Commands\CommandBase.cs:line 30
   at Dnt.Commands.Packages.SwitchPackagesToProjectsCommand.AddProjectsToSolutionAsync(ReferenceSwitcherConfiguration configuration, IConsoleHost host) in C:\projects\dnt\src\Dnt.Commands\Packages\SwitchPackagesToProjectsCommand.cs:line 57
   at Dnt.Commands.Packages.SwitchPackagesToProjectsCommand.RunAsync(CommandLineProcessor processor, IConsoleHost host) in C:\projects\dnt\src\Dnt.Commands\Packages\SwitchPackagesToProjectsCommand.cs:line 29
   at NConsole.CommandLineProcessor.ProcessSingleAsync(String[] args, Object input)
   at NConsole.CommandLineProcessor.ProcessAsync(String[] args, Object input)
   at NConsole.CommandLineProcessor.Process(String[] args, Object input)
   at Dnt.Program.Main(String[] args) in C:\projects\dnt\src\Dnt\Program.cs:line 33

If I take out the ".." and use an absolute path, everything is fine. I updated my DNT installation (I was on 1.9.0 and now I'm on 2.0.1) and it happened with both. I did update Visual Studio to 17.13.0 Preview 3 recently (from Preview 2). Could it possibly be tied to that? Something with the build tools?

[whodges]

Actually, even absolute paths are insufficient when the folder isn't somewhere under the current working directory because the ":" is also banned too.

[whodges]

Last note: when I roll back to 17.13.0 Preview 2.1, the problem goes away. I've submitted a VS ticket.