Model history's prompt is "None" after BootstrapFewShot optimization

[belmarca]

Hi,

I am running a BootstrapFewShot optimizer on a simple model as follows:

        dspy.settings.configure(lm=student_model)

# ...

        config = dict(
            max_bootstrapped_demos=len(examples),
            max_labeled_demos=len(examples),
            teacher_settings=dict(lm=teacher_model),
        )
        optimizer = BootstrapFewShot(metric=metric, **config)

# ...

        run = optimizer.compile(module(), trainset=examples)

I want to get the optimized prompt out of the student_model but its history is empty. When accessing the teacher_model's history, its "prompt" key is None. I am using the new LM class.

This works fine with the old OpenAI class.