Building model before cross-validation

[aolney]

Right now this seems to happen in BaseClassifier.cs

public PmlEvaluation EvaluateWithCrossValidation(int numfolds = 10, bool quiet = false, bool getPredictions = true)
{
Build(quiet);
return new ClassifierEvaluator(Runtime, (IBaseClassifier)this).
EvaluateWithCrossValidateion(numfolds, quiet, getPredictions);
}

However, the WEKA maintainers say that building the model before crossvalidation can lead to incorrect results:

http://weka.8497.n7.nabble.com/Model-serialization-and-prediction-td6574.html