Developer Guide Overview

This guide assumes you have checked-out the repository.

Environment setup

Contributor setup instructions are maintained in CONTRIBUTING.md.

The core Hydra framework supports Python 3.10 through 3.14. You may need to create additional environments for different Python versions if CI detects issues on a supported Python version.

Unsanitized tracebacks

When an application raises, Hydra sanitizes the traceback: it strips its own frames from the top and OmegaConf frames from the bottom, so that what remains points at the application code. That is the right output for someone debugging their own app, but it hides the framework internals needed to diagnose a bug in Hydra itself.

Set HYDRA_FULL_ERROR=1 to disable the sanitization and get the complete Hydra and OmegaConf call stack:

HYDRA_FULL_ERROR=1 python my_app.py

Hydra also skips sanitization automatically when it detects that the process is running under a debugger.

This is a framework debugging facility rather than a troubleshooting step for application users, so Hydra does not suggest it after runtime failures. Ask for it when triaging a bug report that needs the unsanitized traceback.