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esh-pfi-infrastructure/services/meromero-quant/tok_repro.py
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vh 1a5bc2ddf1 Land the MeroMero v2-31B NVFP4A16 quant and record the pinned-transformers trap
The v2 dense quant had failed four times. Attempt 5 lands it at 19 G.

The blocker was not what it looked like. `AmbiguousGlobalPerLayerAttributeError`
on `head_dim` read as a malformed upload -- DogOnKeyboard's config carries a
`per_layer_config` key zerofata's canonical one lacks -- and the standing fix was
to force `allow_global_per_layer_attribute_access=True`. Both halves were wrong.

`pip install llmcompressor==0.13.0` downgrades transformers 5.16.1 -> 5.14.1. The
config was serialized by 5.16.1, which materializes `per_layer_config` from
`global_head_dim` + `layer_types`; 5.14.1 carries the heterogeneity guard but not
the gemma4 resolver. Under the image's own transformers the same config loads
fine. `:latest` was also re-pulled during attempt 4 and no earlier run, so the
toolchain moved mid-diagnosis. Two things separated "malformed upload" from
"moved toolchain": reproducing the real failing call (a bare AutoConfig load does
not reproduce it; the trigger is reached through AutoTokenizer) and keeping
zerofata's canonical tree, quantized cleanly on 2026-08-21, as a positive control.

The fix drops `per_layer_config` rather than forcing global access. It is exactly
redundant -- keys are precisely the ten full_attention layer indices, sole value
(512, 4), verbatim the global fields -- and forcing instead would make
`config.head_dim` answer 256 to the callers building the 512-wide layers.
patch_perlayer.py re-proves that redundancy at apply time and refuses if it ever
stops holding.

Verified on the tensor table rather than the exit code: the output is identical
family-for-family and count-for-count to the August canonical quant, with 356
BF16 vision-tower tensors preserved and input_activations=None. A GPU-free load
leaves 0 tensors on meta and generates coherent prose. The section 4.4 serve test
has NOT run -- GPU1 has 19.9 GB free against 19.5 GB of weights, so it needs a
live seat displaced.

Also fixes the A4B output, which had a truncation cap baked into its tokenizer
(max_length 8192) from being quantized with the calibration corpus.

Playbook gains section 3.17 for the pinned-transformers class and sharpens 3.16
to say drop the dataset outright for any A16 scheme.
2026-09-10 10:56:16 -07:00

68 lines
2.5 KiB
Python

"""Reproduce the ACTUAL failing call, not a paraphrase of it.
quant_a16_datafree.py dies inside `AutoTokenizer.from_pretrained(path,
trust_remote_code=True)`. A bare `AutoConfig.from_pretrained(dir)` does NOT
reproduce it -- I checked, and all four config variants sailed through. So the
trigger lives in the tokenizer path, and testing the config alone would have sent
me off patching a file that was never the problem.
POSITIVE CONTROL, and it is the whole point of this script: zerofata's canonical
v2 tree quantized cleanly on 2026-08-21. If it now fails on this same call, the
config is exonerated and the toolchain moved under us -- `vllm/vllm-openai:latest`
was re-pulled mid-campaign and carries transformers 5.16.1 where the successful
August run had 5.12.1.
"""
import json, os, tempfile, traceback
from pathlib import Path
import transformers
from transformers import AutoTokenizer
print(f"transformers {transformers.__version__}", flush=True)
HERETIC = Path("/tank/aimodels/G4-MeroMero-v2-31B-heretic-bf16")
CANON = Path("/tank/aimodels/meromero-v2-nvfp4-work/src")
# Tokenizer loading reads config.json, so a variant needs the whole tree. Symlink
# everything, then overwrite the one file under test.
def tree(name, src, mutate=None):
d = Path(tempfile.mkdtemp(prefix=f"tok-{name}-"))
for f in src.iterdir():
if f.is_file():
os.symlink(f, d / f.name)
if mutate is not None:
cfg = json.loads((src / "config.json").read_text())
mutate(cfg)
(d / "config.json").unlink()
(d / "config.json").write_text(json.dumps(cfg))
return d
def drop_plc(c):
c["text_config"].pop("per_layer_config", None)
def force_global(c):
c["text_config"]["allow_global_per_layer_attribute_access"] = True
cases = [
("A-canonical-POSITIVE-CONTROL", tree("canon", CANON)),
("B-heretic-asis", tree("heretic", HERETIC)),
("C-heretic-drop-per_layer_config", tree("drop", HERETIC, drop_plc)),
("D-heretic-force-global-access", tree("force", HERETIC, force_global)),
("E-canonical-force-global-access", tree("canonforce", CANON, force_global)),
]
for name, d in cases:
print(f"\n=== {name} ===", flush=True)
try:
tok = AutoTokenizer.from_pretrained(d, trust_remote_code=True)
except Exception as e:
tb = traceback.format_exc().strip().splitlines()
print(f" FAILED {type(e).__name__}")
print(" " + "\n ".join(tb[-4:]))
continue
trunc = getattr(tok, "truncation_side", None)
print(f" OK {type(tok).__name__} vocab={len(tok)} truncation_side={trunc}")