unsloth/studio/backend/utils/transformers_version.py

266 lines
9.5 KiB
Python

"""
Automatic transformers version switching.
Some newer model architectures (Ministral-3, GLM-4.7-Flash, Qwen3-30B-A3B MoE,
tiny_qwen3_moe) require transformers>=5.2.0, while everything else needs the
default 4.57.x that ships with Unsloth.
When loading a LoRA adapter with a custom name, we resolve the base model from
``adapter_config.json`` and check *that* against the model list.
Strategy:
Training and inference run in subprocesses that activate the correct version
via sys.path (prepending .venv_t5/ for 5.x models). See:
- core/training/worker.py
- core/inference/worker.py
For export (still in-process), ensure_transformers_version() does a lightweight
sys.path swap using the same .venv_t5/ directory pre-installed by setup.sh.
"""
import importlib
import json
import logging
import os
import subprocess
import sys
from pathlib import Path
logger = logging.getLogger(__name__)
# Ensure our logger is visible even if root logger isn't configured for INFO.
if not logger.handlers:
_handler = logging.StreamHandler()
_handler.setLevel(logging.INFO)
_handler.setFormatter(
logging.Formatter("[%(name)s|%(levelname)s]%(message)s")
)
logger.addHandler(_handler)
logger.setLevel(logging.INFO)
# ---------------------------------------------------------------------------
# Detection
# ---------------------------------------------------------------------------
# Lowercase substrings — if ANY appears anywhere in the lowered model name,
# we need transformers 5.x.
TRANSFORMERS_5_MODEL_SUBSTRINGS: tuple[str, ...] = (
"ministral-3-", # Ministral-3-{3,8,14}B-{Instruct,Reasoning,Base}-2512
"glm-4.7-flash", # GLM-4.7-Flash
"qwen3-30b-a3b", # Qwen3-30B-A3B-Instruct-2507 and variants
"qwen3.5", # Qwen3.5 family (35B-A3B, etc.)
"qwen3-next", # Qwen3-Next and variants
"tiny_qwen3_moe", # imdatta0/tiny_qwen3_moe_2.8B_0.7B
)
# Versions
TRANSFORMERS_5_VERSION = "5.2.0"
TRANSFORMERS_DEFAULT_VERSION = "4.57.1"
# Pre-installed directory for transformers 5.x — created by setup.sh / setup.ps1
_PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent.parent # studio/backend/utils/ → project root
_VENV_T5_DIR = str(_PROJECT_ROOT / ".venv_t5")
def _resolve_base_model(model_name: str) -> str:
"""If *model_name* points to a LoRA adapter, return its base model.
Checks for ``adapter_config.json`` locally first. Only calls the heavier
``get_base_model_from_lora`` for paths that are actual local directories
(avoids noisy warnings for plain HF model IDs).
Returns the original *model_name* unchanged if it is not a LoRA adapter.
"""
# --- Fast local check ---------------------------------------------------
local_path = Path(model_name)
adapter_cfg_path = local_path / "adapter_config.json"
if adapter_cfg_path.is_file():
try:
with open(adapter_cfg_path) as f:
cfg = json.load(f)
base = cfg.get("base_model_name_or_path")
if base:
logger.info(
"Resolved LoRA adapter '%s' → base model '%s'",
model_name, base,
)
return base
except Exception as exc:
logger.debug("Could not read %s: %s", adapter_cfg_path, exc)
# --- Only try the heavier fallback for local directories ----------------
if local_path.is_dir():
try:
from utils.models import get_base_model_from_lora
base = get_base_model_from_lora(model_name)
if base:
logger.info(
"Resolved LoRA adapter '%s' → base model '%s' "
"(via get_base_model_from_lora)",
model_name, base,
)
return base
except Exception as exc:
logger.debug(
"get_base_model_from_lora failed for '%s': %s",
model_name, exc,
)
return model_name
def needs_transformers_5(model_name: str) -> bool:
"""Return True if *model_name* belongs to an architecture that requires
``transformers>=5.2.0``."""
lowered = model_name.lower()
return any(sub in lowered for sub in TRANSFORMERS_5_MODEL_SUBSTRINGS)
# ---------------------------------------------------------------------------
# Version switching (in-process — used only by export)
# ---------------------------------------------------------------------------
def _get_in_memory_version() -> str | None:
"""Return the transformers version currently loaded in this process."""
tf = sys.modules.get("transformers")
if tf is not None:
return getattr(tf, "__version__", None)
return None
# All top-level prefixes that hold references to transformers internals.
_PURGE_PREFIXES = (
"transformers",
"huggingface_hub",
"unsloth",
"unsloth_zoo",
"peft",
"trl",
"accelerate",
"auto_gptq",
# NOTE: bitsandbytes is intentionally EXCLUDED — it registers torch custom
# operators at import time via torch.library.define(). Those registrations
# live in torch's global operator registry which survives module purge.
# Re-importing bitsandbytes after purge → duplicate registration → crash.
# Our own modules that import from transformers at module level
# (e.g. model_config.py: `from transformers import AutoConfig`)
"utils.models",
"core.training",
"core.inference",
"core.export",
)
def _purge_modules() -> int:
"""Remove all cached modules for transformers and its dependents.
Returns the number of modules purged.
"""
importlib.invalidate_caches()
to_remove = [
k for k in list(sys.modules.keys())
if any(k == p or k.startswith(p + ".") for p in _PURGE_PREFIXES)
]
for key in to_remove:
del sys.modules[key]
return len(to_remove)
def _ensure_venv_t5_exists() -> bool:
"""Ensure .venv_t5/ exists. Install at runtime if missing."""
if os.path.isdir(_VENV_T5_DIR) and os.listdir(_VENV_T5_DIR):
return True
logger.warning(".venv_t5 not found at %s — installing at runtime", _VENV_T5_DIR)
os.makedirs(_VENV_T5_DIR, exist_ok=True)
for pkg in (f"transformers=={TRANSFORMERS_5_VERSION}", "huggingface_hub==1.3.0"):
cmd = [
sys.executable, "-m", "pip", "install",
"--target", _VENV_T5_DIR,
"--no-deps",
pkg,
]
result = subprocess.run(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True)
if result.returncode != 0:
logger.error("pip install failed:\n%s", result.stdout)
return False
logger.info("Installed transformers 5.x to %s", _VENV_T5_DIR)
return True
def _activate_5x() -> None:
"""Prepend .venv_t5/ to sys.path, purge stale modules, reimport."""
if not _ensure_venv_t5_exists():
raise RuntimeError(f"Cannot activate transformers 5.x: .venv_t5 missing at {_VENV_T5_DIR}")
if _VENV_T5_DIR not in sys.path:
sys.path.insert(0, _VENV_T5_DIR)
logger.info("Prepended %s to sys.path", _VENV_T5_DIR)
count = _purge_modules()
logger.info("Purged %d cached modules", count)
import transformers
logger.info("Loaded transformers %s", transformers.__version__)
def _deactivate_5x() -> None:
"""Remove .venv_t5/ from sys.path, purge stale modules, reimport."""
while _VENV_T5_DIR in sys.path:
sys.path.remove(_VENV_T5_DIR)
logger.info("Removed %s from sys.path", _VENV_T5_DIR)
count = _purge_modules()
logger.info("Purged %d cached modules", count)
import transformers
logger.info("Reverted to transformers %s", transformers.__version__)
def ensure_transformers_version(model_name: str) -> None:
"""Ensure the correct ``transformers`` version is active for *model_name*.
Uses sys.path with .venv_t5/ (pre-installed by setup.sh):
• Need 5.x → prepend .venv_t5/ to sys.path, purge modules.
• Need 4.x → remove .venv_t5/ from sys.path, purge modules.
For LoRA adapters with custom names, the base model is resolved from
``adapter_config.json`` before checking.
NOTE: Training and inference use subprocess isolation instead of this
function. This is only used by the export path (routes/export.py).
"""
# Resolve LoRA adapters to their base model for accurate detection
resolved = _resolve_base_model(model_name)
want_5 = needs_transformers_5(resolved)
target_version = TRANSFORMERS_5_VERSION if want_5 else TRANSFORMERS_DEFAULT_VERSION
target_major = int(target_version.split(".")[0])
# Check what's actually loaded in memory
in_memory = _get_in_memory_version()
logger.info(
"Version check for '%s' (resolved: '%s'): need=%s, in_memory=%s",
model_name, resolved, target_version, in_memory,
)
# --- Already correct? ---------------------------------------------------
if in_memory is not None:
in_memory_major = int(in_memory.split(".")[0])
if in_memory_major == target_major:
logger.info(
"transformers %s already loaded — correct for '%s'",
in_memory, model_name,
)
return
# --- Switch version -----------------------------------------------------
if want_5:
logger.info("Activating transformers %s via .venv_t5…", TRANSFORMERS_5_VERSION)
_activate_5x()
else:
logger.info("Reverting to default transformers %s", TRANSFORMERS_DEFAULT_VERSION)
_deactivate_5x()
final = _get_in_memory_version()
logger.info("✓ transformers version is now %s", final)