fix: extend error message in case there are uncommited changes, in or…

…der to get the files which are causing the issue (#666)

* fix: extend error message in case there are uncommited changes, in order to get the files which are causing the issue

This will make it possible, that the .gitignore file will be extended to exclude the temp files who are causing the issue in related repos. This fix is related to #603

src/NerdBank.GitVersioning/ReleaseManager.cs

@@ -3,6 +3,7 @@
     using System;
     using System.Collections.Generic;
     using System.IO;
+    using System.Linq;
     using LibGit2Sharp;
     using Nerdbank.GitVersioning.LibGit2;
     using Newtonsoft.Json;
@@ -408,9 +409,13 @@ private LibGit2Context GetRepository(string projectDirectory)
 
 
             // abort if there are any pending changes
-            if (libgit2context.Repository.RetrieveStatus().IsDirty)
+            var status = libgit2context.Repository.RetrieveStatus();
+            if (status.IsDirty)
             {
-                this.stderr.WriteLine($"Uncommitted changes in directory '{projectDirectory}'.");
+                var changedFiles = status.OfType<StatusEntry>().ToList();
+                var changesFilesFormatted = string.Join(Environment.NewLine, changedFiles.Select(t => $"- {t.FilePath} changed with {nameof(FileStatus)} {t.State}"));
+                this.stderr.WriteLine($"Uncommitted changes ({changedFiles.Count}) in directory '{projectDirectory}':");
+                this.stderr.WriteLine(changesFilesFormatted);
                 throw new ReleasePreparationException(ReleasePreparationError.UncommittedChanges);
             }