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name: weight-diff-recovery description: "Guide Alpaca weight-diff creation and recovery, path-role validation, tokenizer pad-token resizing, integrity checks, and safe dry-run planning." disable-model-invocation: true metadata: disco-role: operating license: NOASSERTION

Weight Diff Recovery

Use this sub-skill when the task is about Alpaca/LLaMA weight diffs rather than supervised fine-tuning or data generation.

Route Here For

• Recovering Alpaca weights from the released diff after the raw Meta LLaMA checkpoint has been converted to Hugging Face format.
• Creating a fresh weight diff from a raw/tuned checkpoint pair.
• Checking checkpoint path roles, output locations, device choice, tokenizer pad-token resizing, naive integrity checks, or a short inference smoke run.
• Planning a recovery command without loading checkpoints yet.

Route Elsewhere

• Supervised fine-tuning, later downstream use of recovered weights, or training recipes: ../fine-tuning/SKILL.md
• License/intended-use context, prompt provenance, or dataset handling: ../dataset-and-prompts/SKILL.md
• Prompt synthesis or seed-task generation details: ../instruction-generation/SKILL.md

Fast Workflow

1. Confirm the mode:
   • recover: path_raw + path_diff -> optional path_tuned
   • make_diff: path_raw + path_tuned -> path_diff
2. Verify prerequisites before any live load:
   • path_raw points to the Hugging Face-converted LLaMA checkpoint directory.
   • path_diff points to the released Alpaca weight-diff directory.
   • path_tuned is either the tuned input for make_diff or the recovery output directory for recover.
   • You have the relevant LLaMA access and non-commercial license context for the diff/artifacts; read the bundled intended-use and licenses reference before sharing outputs.
3. Run scripts/build_weight_diff_command.py to validate the path roles and print a safe dry-run command.
4. If you intend to execute, use scripts/alpaca_weight_diff.py with the chosen device.
5. Treat the checksum and smoke inference as sanity checks only.

Key Rules

• make_diff computes diff-minus-raw; recover computes diff-plus-raw.
• When the raw tokenizer has no pad token, resize the tokenizer and both embedding matrices before subtraction/addition.
• device="cpu" is the safest inspection default. Switch to cuda only if the hardware is available and the checkpoint fits.
• path_tuned is optional on recover; when omitted, nothing is saved.
• The naive checksum is a heuristic. A matching value is useful, but a mismatch is not a cryptographic proof of failure.
• The inference smoke is qualitative only and can fail for prompt-format, device, or memory reasons unrelated to weight correctness.

References and scripts

• Read workflows for recover/make-diff recipes, path roles, and execution gates.
• Read API reference for verified function signatures, parameters, and return/save behavior.
• Read troubleshooting for missing checkpoints, tokenizer mismatches, OOM, device errors, and checksum failures.
• Run build_weight_diff_command.py to validate path roles and print a dry-run command before tensor loads.
• Run alpaca_weight_diff.py only when you intentionally want the self-contained live/dry-run runner.