extended diagnostics

frontend/pweb/lib/main.dart

@@ -42,10 +42,17 @@ final _bootstrapLogger = Logger('bootstrap');
 void _setupLogging() {
   Logger.root.level = Level.ALL;
   Logger.root.onRecord.listen((record) {
-    // ignore: avoid_print
-    print(
+    final buffer = StringBuffer(
       '${record.level.name}: ${record.time}: ${record.loggerName}: ${record.message}',
     );
+    if (record.error != null) {
+      buffer.write('\nerror: ${record.error}');
+    }
+    if (record.stackTrace != null) {
+      buffer.write('\n${record.stackTrace}');
+    }
+    // ignore: avoid_print
+    print(buffer.toString());
   });
 }
 
@@ -65,7 +72,6 @@ void _setupErrorHandling() {
   };
 }
 
-
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   _setupLogging();