Don't swallow unexpected exceptions form LibGit2Sharp; they might be very valuable for debugging purposes.

Author: asbjornu

src/GitVersionCore/GitPreparer.cs

@@ -191,7 +191,7 @@ static void CloneRepository(string repositoryUrl, string gitDirectory, Authentic
                     throw new Exception("Not found: The repository was not found");
                 }
 
-                throw new Exception("There was an unknown problem with the Git repository you provided");
+                throw new Exception("There was an unknown problem with the Git repository you provided", ex);
             }
         }
     }