Persistent Dependency, CUDA, and Authentication Failures Prevent Running SynthID Text Colab Notebook in Free T4 GPU Runtime

[bug0error]

Title: Persistent Dependency, CUDA, and Authentication Failures Prevent Running SynthID Text Colab Notebook in Free T4 GPU Runtime

Target Notebook: google-deepmind/synthid-text/notebooks/synthid_text_huggingface_integration.ipynb

Description:

I am a user attempting to validate the robustness of the SynthID Text watermarking for Chinese text using the official Colab notebook. Despite following instructions (including guidance from an AI assistant) and attempting troubleshooting for an entire night, the notebook consistently fails to execute end-to-end in the Google Colab Free Tier T4 GPU runtime.

The persistence of these errors suggests a fundamental incompatibility between the notebook's static dependency requirements and the current Colab environment.

Detailed Error Chain (Chronological Order):

1. Initial Dependency and Version Conflicts (Recurring):

• Error Symptom: The initial pip install cell throws repeated "ERROR: pip's dependency resolver does not currently take into account..." warnings.
• Specific Conflict: Conflicts were noted between system-installed libraries (e.g., torchaudio, torchvision, pytensor) requiring torch 2.8.0 and numpy >= 2.0, and the installed versions (torch 2.4.0 and numpy 1.26.0).
• Troubleshooting: Repeated attempts at "Restart runtime" and "Disconnect and delete runtime" (Factory Reset) failed to eliminate the environment conflict.

2. Model Access Error (Gemma):

• Error Type: HTTPError: 401 Client Error: Unauthorized / GatedRepoError
• Description: The notebook failed to load the default model (google/gemma-7b-it) due to requiring Hugging Face authentication and license acceptance.
• Workaround: Successfully changed the model identifier to the fully public 'gpt2'.

3. Final, Unresolvable GPU Error (Occurring with GPT-2 Model):

• Error Type: RuntimeError: CUDA error: device-side assert triggered
• Description: This fatal error occurred during the LogitsProcessor initialization stage (specifically at torch.tensor(keys, device=device)). This indicates a deep, unresolved incompatibility between the installed SynthID library version and the current Colab GPU environment.
• Conclusion: The Colab script is currently unusable for a non-expert user in the default Colab GPU environment.

User Request (Action Items):

1. Please fix the dependency issue so the notebook runs seamlessly in the standard Colab Free Tier T4 GPU runtime without requiring manual code changes or multiple restarts.
2. Or, provide a pre-configured CPU-only version that explicitly avoids CUDA dependencies, offering a stable experience for research verification.