"""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}")