Bug in Zipline?

Hi y'all am getting this bug when I try execute allocated trades using zipline. The code works fine in simulation. Is this a bug?

Traceback (most recent call last): 
  File "sym://qrocket_log_py", line 34, in wrapped 
  File "sym://qrocket_qrzipline_trade_trade_py", line 57, in mule_trade_algo 
  File "/opt/conda/lib/python3.8/site-packages/zipline/algorithm.py", line 652, in run 
  File "sym://qrocket_qrzipline_trade_trade_py", line 179, in trade_algo 
  File "/opt/conda/lib/python3.8/site-packages/zipline/gens/tradesimulation.py", line 182, in transform 
    for capital_change_packet in every_bar(dt): 
    for perf in self.get_generator(): 
  File "/opt/conda/lib/python3.8/site-packages/zipline/gens/tradesimulation.py", line 117, in every_bar 
    handle_data(algo, current_data, dt_to_use) 
  File "/opt/conda/lib/python3.8/site-packages/zipline/utils/events.py", line 216, in handle_data 
    event.handle_data( 
  File "/opt/conda/lib/python3.8/site-packages/zipline/utils/events.py", line 238, in handle_data 
    self.callback(context, data) 
  File "trend_weekly", line 258, in select_stocks_and_set_weights 
    res = self.eval(expr, **kwargs) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/frame.py", line 3466, in query 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/frame.py", line 3596, in eval 
    return _eval(expr, inplace=inplace, **kwargs) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/eval.py", line 342, in eval 
    parsed_expr = Expr(expr, engine=engine, parser=parser, env=env) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 798, in __init__ 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 817, in parse 
    return self._visitor.visit(self.expr) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 401, in visit 
    return self.visit(expr, **kwargs) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 407, in visit_Module 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 401, in visit 
    return self.visit(node.value, **kwargs) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 410, in visit_Expr 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 401, in visit 
    return reduce(visitor, operands) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 737, in visit_BoolOp 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 731, in visitor 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 726, in _try_visit_binop 
    return self.visit(bop) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 401, in visit 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 737, in visit_BoolOp 
    self.terms = self.parse() 
    return visitor(node, **kwargs) 
    return visitor(node, **kwargs) 
    return visitor(node, **kwargs) 
    rhs = self._try_visit_binop(y) 
    return visitor(node, **kwargs) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 734, in visitor 
    return reduce(visitor, operands) 
    return self._maybe_evaluate_binop(op, node.op, lhs, rhs) e-packages/pandas/core/computation/expr.py", line 518, in _maybe_evaluate_binop 
    return self._maybe_eval(res, eval_in_python + maybe_eval_in_python) 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/expr.py", line 478, in _maybe_eval 
    return binop.evaluate( 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/ops.py", line 433, in evaluate 
    right = self.rhs.evaluate( 
  File "/opt/conda/lib/python3.8/site-packages/pandas/core/computation/ops.py", line 425, in evaluate 
    left = self.lhs.evaluate( 
AttributeError: 'UnaryOp' object has no attribute 'evaluate' 

The traceback (which should be read from bottom to top) points you back to the line in your zipline file that is triggering the error:

File "trend_weekly", line 258, in select_stocks_and_set_weights 

Start there. There are any number of reasons why you might experience an error in trading but not backtesting.

@Brian - thanks! I think I figured it out.