Fixing an issue in the RepoDirectoriesProvider where it assumed that the only directory under SDK was the SDK directories. This is no longer true now that we moved the NuGet fallback folder there.

Author: livarcocc

test/Microsoft.DotNet.Tools.Tests.Utilities/RepoDirectoriesProvider.cs

@@ -98,7 +98,10 @@ public RepoDirectoriesProvider(
             _builtDotnet = builtDotnet ?? Path.Combine(_artifacts, "intermediate", "sharedFrameworkPublish");
             _nugetPackages = nugetPackages ?? Path.Combine(RepoRoot, ".nuget", "packages");
             _pjDotnet = pjDotnet ?? GetPjDotnetPath();
-            _stage2Sdk = Directory.EnumerateDirectories(Path.Combine(_artifacts, "stage2", "sdk")).First();
+            _stage2Sdk = Directory
+                .EnumerateDirectories(Path.Combine(_artifacts, "stage2", "sdk"))
+                .First(d => !d.Contains("NuGetFallbackFolder"));
+
             _stage2WithBackwardsCompatibleRuntimesDirectory =
                 Path.Combine(_artifacts, "stage2WithBackwardsCompatibleRuntimes");
             _testPackages = Path.Combine(RepoRoot, "artifacts", "testpackages", "packages");