fix: avoid duplicate base class insertion

Author: edarchimbaud

alphaevolve/evolution/controller.py

@@ -120,9 +120,12 @@ async def _spawn(self, parent_id: str | None, *, prompt: PromptGenome | None = N
 
  child_strategy = apply_patch(parent["code"], diff_json)
 
- imports = "from collections import deque\nimport backtrader as bt"
- base_cls = inspect.getsource(BaseLoggingStrategy)
- child_code = textwrap.dedent(imports + "\n\n" + base_cls + "\n\n" + child_strategy)
+ if "class BaseLoggingStrategy" not in child_strategy:
+ imports = "from collections import deque\nimport backtrader as bt"
+ base_cls = inspect.getsource(BaseLoggingStrategy)
+ child_code = textwrap.dedent(imports + "\n\n" + base_cls + "\n\n" + child_strategy)
+ else:
+ child_code = textwrap.dedent(child_strategy)
 
  # 4) Evaluate
  try: