[MIPRO_v2] error in bootstrapping few-shot examples raises TypeError

[mikeedjones]

Any error raised whilst generating bootstrap examples is handled and sets demo_candidates = None

255            except Exception as e:
256                print(f"Error generating fewshot examples: {e}")
257                print("Running without fewshot examples.")
258                demo_candidates = None

which causes a type error with grounded_proposer.

    305 # Create an instruction for each predictor 
    306 for pred_i, predictor in enumerate(program.predictors()):
--> 307     for demo_set_i in range(len(demo_candidates[0])):
    308         if pred_i not in proposed_instructions:
    309             proposed_instructions[pred_i] = []

TypeError: 'NoneType' object is not subscriptable

Not sure if this should be fixed by either:

• Raising an exception if there is an error during bootstrapping
• Setting demo_candidates={} in MIPRO_v2
• Accounting for demo_candidates is None in proposer.propose_instructions_for_program

Or something else :)

[okhat]

@XenonMolecule Can you investigate?

[XenonMolecule]

@mikeedjones can you see if #1581 works for you? I tested on a few internal programs by simulating an exception during bootstrapping, but I would love to know if this fixes your real test case.