Cannot export XGBClassifier model: TypeError: unsupported operand type(s) for /: 'float' and 'NoneType'

``` import xgboost as xgb import numpy as np import m2cgen as m2c from sklearn.datasets import load_boston # train a model and save it as c code with m2cgen X, y = load_boston(return_X_y=True) y = np.random.choice([0, 1], size=len(y)) model = xgb.XGBClassifier(n_estimators=10, max_depth=3) model.fit(X, y) code = m2c.export_to_c(model) ``` Works fine with XGBoostRegressor Full trace: ``` Traceback (most recent call last): File "/Applications/PyCharm.app/Contents/plugins/python/helpers/pydev/pydevd.py", line 1500, in _exec pydev_imports.execfile(file, globals, locals) # execute the script ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Applications/PyCharm.app/Contents/plugins/python/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc) File "/Users/judewells/Documents/dataScienceProgramming/tethir/ir3flamedetect2/experiment_scripts/temp_file_m2c.py", line 13, in <module> code = m2c.export_to_c(model) ^^^^^^^^^^^^^^^^^^^^^^ File "/Users/judewells/miniforge3/envs/bayes_opt/lib/python3.11/site-packages/m2cgen/exporters.py", line 81, in export_to_c return _export(model, interpreter) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/judewells/miniforge3/envs/bayes_opt/lib/python3.11/site-packages/m2cgen/exporters.py", line 459, in _export model_ast = assembler_cls(model).assemble() ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/judewells/miniforge3/envs/bayes_opt/lib/python3.11/site-packages/m2cgen/assemblers/boosting.py", line 214, in assemble return self.assembler.assemble() ^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/judewells/miniforge3/envs/bayes_opt/lib/python3.11/site-packages/m2cgen/assemblers/boosting.py", line 34, in assemble return self._assemble_bin_class_output(self._all_estimator_params) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/judewells/miniforge3/envs/bayes_opt/lib/python3.11/site-packages/m2cgen/assemblers/boosting.py", line 80, in _assemble_bin_class_output base_score = -math.log(1.0 / self._base_score - 1.0) ~~~~^~~~~~~~~~~~~~~~~~ TypeError: unsupported operand type(s) for /: 'float' and 'NoneType' ``` Using m1 MacBook pro. xgboost version '2.0.3' (also got the same error using older version)