Restructure the MLX smoke test into a multi-step workflow that
exercises the export round-trip the way real users hit it: each
reload runs in a FRESH Python process (not a continuation of the
still-running trainer), and each step emits a JSON metrics file
with elapsed time + peak GPU memory + peak RSS for regression
detection.
Steps (each on the macos-14 M1 standard runner, FREE for public
repos):
1. TRAIN + SAVE 3 formats
- Load unsloth/gemma-3-270m-it (fp16, no quant).
- Apply LoRA r=8 on q/k/v/o.
- Pre-train + post-train loss + grad norm probe via
mx.nn.value_and_grad on the training row.
- Train 7 deterministic steps, batch_size=2,
gradient_accumulation_steps=3 (42 sequences trained), capture
per-step loss via add_step_callback.
- In-memory generate -> assert "Unsloth" appears.
- Save LoRA, merged_16bit, GGUF.
- Emit mlx_workdir/train_metrics.json.
2. RELOAD LoRA (fresh process)
FastMLXModel.from_pretrained(lora_dir) cold-load + generate +
assert "Unsloth" appears. Emits lora_reload_metrics.json.
3. RELOAD merged_16bit (fresh process)
Same flow on the merged HF directory.
4. RELOAD GGUF via llama-cli (fresh process)
Conditional on train_metrics.json:gguf_supported. Spawns the
llama-cli built by save_pretrained_gguf with --temp 0
--seed 3407 -no-cnv and asserts "Unsloth" in stdout. The
per-phase metrics step prints all four JSON files so
regressions are visible in the job log.
Pin unsloth_zoo to fix/mlx-export-roundtrip-on-apple-silicon while
unslothai/unsloth-zoo#627 is in review -- it carries:
- llama_cpp.py: catch NotImplementedError too when importing
device_is_bf16_supported (device_type module-level call raises
on Apple Silicon).
- mlx_loader.py: don't wipe local_path when config.json is
missing, otherwise FastMLXModel.from_pretrained(lora_dir)
can't see adapter_config.json.
The earlier draft of this script had a workaround that copied the
base model's config.json into the LoRA save dir; with #627 the
workaround is removed, the cold-start LoRA reload works on the
saved adapter directory directly.
Workflow timeout already 25 min for the llama.cpp cmake build.
246f54d05a