Merge pull request #6526 from mikkelbu/fail-gracefully-when-multiple-project-exist

Fail gracefully when multiple projects exist

src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectFactory.cs

@@ -80,7 +80,7 @@ namespace Microsoft.DotNet.Cli.Utils
             }
             else if (projectFiles.Count() > 1)
             {
-                throw new InvalidOperationException(string.Format(
+                throw new GracefulException(string.Format(
                     LocalizableStrings.MultipleProjectFilesFound,
                     projectDirectory));
             }