[OnePunchMonk]

Fixes #43873

Motivation

On ComfyUI v0.39.2, every integrated-mode model (SGLDUNETLoader) fails to load. The node raises "The SGLD worker exited while loading the model", and the worker log shows:

File "ComfyUI/main.py", line 25, in <module>
  from app.database.db import ...
File "ComfyUI/app/database/db.py", line 9, in <module>
  from utils.install_util import get_missing_requirements_message
ModuleNotFoundError: No module named 'utils.install_util'; 'utils' is not a package

The worker is started with multiprocessing spawn, so the child re-imports the parent's __main__, which under ComfyUI is main.py. ComfyUI's nodes.py puts ComfyUI/comfy first on sys.path, so in the child import utils.install_util finds comfy/utils.py instead of ComfyUI's utils/ package.

Modifications

• Hide __main__.__file__ / __spec__ only while DiffGenerator.from_pretrained starts the workers, then restore them. The worker never runs ComfyUI's entry script; it only needs sglang modules.
• Regression test that spawns a real worker through init_generator from a host script that fails when re-imported, like ComfyUI's main.py.

Accuracy Tests

No change to model outputs. End to end check with ComfyUI v0.39.2 started the normal way (python main.py) and a Flux.1-dev SGLDUNETLoader workflow (1024x1024, 25 steps):

• main, T4: the worker dies with the 'utils' is not a package error above.
• This branch, L40S: the worker starts and the workflow completes.

Speed Tests and Profiling

N/A

Checklist

• Format your code according to the Format code with pre-commit.
• Add unit tests according to the Run and add unit tests. The new test fails on main and passes here; test_comfyui_generator.py, test_comfyui_adapters.py, test_comfyui_session.py: 59 passed on a T4.
• Update documentation according to Write documentations.
• Provide accuracy and speed benchmark results according to Test the accuracy and Benchmark the speed.
• Follow the SGLang code style guidance.

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CI States

Latest PR Test (Base): ❌ Run #38280102285
Latest PR Test (Extra): ❌ Run #38280101950
Latest PR Test (AMD ROCm 10): ❌ Run #38280102570

[niehen6174]

Thanks! This is already fixed in #43504 (same approach, _spawn_without_launcher_main). Mind closing this one?