This moves Hydra away from rigid inheritance trees (which often broke) toward a more flexible composition model. You can now write:
Version 1.2 introduces for certain resolver functions. Early benchmarks show a 40% reduction in instantiation time for large config suites. 5. Deprecation of hydra.main This is the breaking change you need to watch for. The decorator @hydra.main() has been a staple since day one. It now throws a DeprecationWarning . In Hydra 2.0 (planned for Q3 2026), it will be removed. hydra 1.2
# Old (Hydra 1.1) @hydra.main(config_path="conf", config_name="config") def main(cfg): ... def main(): cfg = hydra.initialize_and_run(config_path="conf", config_name="config", task_function=my_task) This moves Hydra away from rigid inheritance trees
pip install hydra-core --upgrade Happy composing! Let us know in the comments if you have found the 1.2 resolver syntax tricky—I will be writing a deep dive on that next week. It now throws a DeprecationWarning
Last week, the team released , and it is not just a minor patch—it changes how we think about configuration composition.
This change allows for better type checking and allows you to run Hydra inside Jupyter Notebooks (finally!) without weird hacks. Yes, but carefully. If you are starting a new project today, use Hydra 1.2 . The new composition rules and Jupyter support are worth it.
Navigating the Labyrinth: What’s New in Hydra 1.2