Improve error reporting and diff output for updates

- Store both old and new values in updates for proper diff reporting
- Show before/after states for updated records in diff mode
- Improve exception handling with better error messages and traceback logging
- Include full exception type if string representation is empty
- Add debug-level traceback output for troubleshooting

plugins/modules/nsupdate_zone.py

@@ -665,7 +665,14 @@ class DNSZoneManager:
                     # Record exists - check if values differ
                     current = current_records[key]
                     if desired['values'] != current['values'] or desired['ttl'] != current['ttl']:
-                        changes['updates'].append(desired)
+                        changes['updates'].append({
+                            'name': desired['name'],
+                            'type': desired['type'],
+                            'old_values': current['values'],
+                            'new_values': desired['values'],
+                            'old_ttl': current['ttl'],
+                            'new_ttl': desired['ttl']
+                        })
                         if self.module._verbosity >= 1 or self.module._diff:
                             before_values = ', '.join(str(v) for v in current['values'])
                             after_values = ', '.join(str(v) for v in desired['values'])
@@ -846,8 +853,15 @@ class DNSZoneManager:
             return result
             
         except Exception as e:
-            result['error'] = str(e)
+            import traceback
+            error_msg = str(e)
+            if not error_msg or error_msg == "":
+                error_msg = f"{type(e).__name__}: {e}"
+            result['error'] = error_msg
             result['failed'] = True
+            # Include traceback in debug output for troubleshooting
+            if self.module._verbosity >= 2:
+                self.module.debug(f"[{self.zone_name_str}] Exception traceback: {traceback.format_exc()}")
             return result
     
     def _format_diff(self, changes: dict) -> dict:
@@ -865,12 +879,11 @@ class DNSZoneManager:
             record_key = f"{record['name'].to_text()} {record['type']}"
             diff_before[record_key] = sorted(str(v) for v in record['values'])
         
-        # Process updates
+        # Process updates - show both before and after
         for record in changes['updates']:
             record_key = f"{record['name'].to_text()} {record['type']}"
-            # For updates, we need to show before state from current_records
+            diff_before[record_key] = sorted(str(v) for v in record['old_values'])
-            # Since we don't have it here, we'll just show after state
+            diff_after[record_key] = sorted(str(v) for v in record['new_values'])
-            diff_after[record_key] = sorted(str(v) for v in record['values'])
         
         return {
             'before': diff_before,