fixing some warnings

Author: arturcic

src/GitVersion.App/ArgumentParser.cs

@@ -166,7 +166,7 @@ private void ParseTargetPath(Arguments arguments, string? name, IReadOnlyList<st
         {
             EnsureArgumentValueCount(values);
             arguments.TargetPath = value;
-            if (!this.fileSystem.DirectoryExists(value))
+            if (string.IsNullOrWhiteSpace(value) || !this.fileSystem.DirectoryExists(value))
             {
                 this.console.WriteLine($"The working directory '{value}' does not exist.");
             }

src/GitVersion.Core/Core/GitPreparer.cs

@@ -114,6 +114,10 @@ private void CreateDynamicRepository(string? targetBranch)
         {
             var gitVersionOptions = this.options.Value;
             var authentication = gitVersionOptions.AuthenticationInfo;
+            if (string.IsNullOrWhiteSpace(gitDirectory))
+            {
+                throw new("Dynamic Git repositories should have a path specified");
+            }
             if (!this.fileSystem.DirectoryExists(gitDirectory))
             {
                 CloneRepository(gitVersionOptions.RepositoryInfo.TargetUrl, gitDirectory, authentication);