ultralytics 8.4.29

v8.4.29 - `ultralytics 8.4.29` Training `resume` fixes (#24021)

on Python PyPI

🌟 Summary

Ultralytics v8.4.29 is mainly a training reliability release 🔧—it makes resume=True much safer and clearer, while also adding a helpful new COCO JSON training guide and small CI/docs/test maintenance updates.

📊 Key Changes

• Major (current PR #24021 by @glenn-jocher): safer training resume flow 🔄✅

  • resume=True now only resumes if the checkpoint truly contains resumable training state (like epoch + optimizer state).
  • If the loaded file is just a model weight file (not a full training checkpoint), Ultralytics now:
    • warns clearly ⚠️
    • and falls back to fresh training instead of silently misbehaving.
  • Trainer-side validation is stricter and explicitly rejects invalid resume checkpoints 🚫.
  • Still supports overriding practical run settings during resume (like imgsz, batch, device, workers, cache, patience, validation flags, etc.) ⚙️.
  • Package version bumped from 8.4.28 to 8.4.29 📦.

• New docs feature (PR #24005 + cleanup in #24022): train directly from COCO JSON 📘

  • Added a full guide for training YOLO models on COCO JSON annotations without converting to YOLO .txt labels.
  • Includes custom dataset/trainer pattern, caching behavior, config examples, and FAQ.
  • Follow-up polish improved formatting/readability and fixed YAML indentation clarity.

• CI benchmark alignment with latest model family (PR #23965) 🚀

  • Docker benchmark workflow now uses YOLO26n instead of YOLO11n, aligning CI with current recommended models.

• Stability and maintenance 🧪

  • Prediction test asset URL switched to a more reliable CDN path for zidane.jpg.
  • Example dependency bumps in RTDETR ONNXRuntime example (onnx, requests).

🎯 Purpose & Impact

• For trainers and ML engineers: fewer resume-related surprises, clearer errors, and safer checkpoint handling during interrupted or restarted runs 🛡️.
• For teams running long jobs: reduces risk of accidentally “resuming” from non-resumable files and wasting compute/time ⏱️.
• For users with COCO datasets: easier path to experiment without annotation conversion pipelines, while keeping JSON as source of truth 🧩.
• For platform/CI reliability: benchmark and test updates improve confidence that container/testing flows reflect current recommended YOLO26 usage 📈.

What's Changed

• Update Docker Benchmarks CI to YOLO26 by @lakshanthad in #23965
• add guide for training YOLO on COCO JSON without conversion by @raimbekovm in #24005
• Use jsdelivr CDN assets URL for zidane.jpg reliability by @glenn-jocher in #24022
• Bump the pip group across 1 directory with 2 updates by @dependabot[bot] in #24024
• ultralytics 8.4.29 Training resume fixes by @glenn-jocher in #24021

Full Changelog: v8.4.28...v8.4.29