Add tests/studio/run_real_mlx_smoke.py and wire it into the macos-14
job as the final step. The script trains unsloth/gemma-3-270m-it
for 7 deterministic LoRA steps on an in-memory dataset of the SAME
row repeated:
"<<HELLO!!>> My name is Unsloth!"
then prompts the trained model with "<<HELLO!!>> My name is " and
asserts the completion contains "Unsloth". Captures and asserts:
- per-step training loss (via MLXTrainer.add_step_callback);
- pre- and post-training loss + gradient norm (computed manually via
mx.nn.value_and_grad over the training row, since MLXTrainer does
not currently expose per-step grad norms);
- losses are finite, do not diverge, and post-train loss < pre-train;
- grad norms are finite and positive;
- the inference output contains "Unsloth".
Determinism: seeds python random, numpy, and mlx.core.random; passes
random_state=SEED to FastMLXModel.from_pretrained and
get_peft_model (both invoke _seed_mlx_random_state internally) and
seed=SEED to MLXTrainingConfig (drives batch shuffling). Uses fp16
+ no quant (gemma-3-270m is small enough to skip 4-bit) and LoRA
r=8 on the four attention projections.
This is the only place in CI that exercises a real MLX backward
pass + optimizer step + mlx_lm.generate call.
c7e3989d72