# Run the Test Suite and Triage Failures in Apache Airflow with Atlas in 2026 > Atlas empowers Apache Airflow developers to quickly identify and prioritize distinct root causes from `pytest (DagBag)` test failures, streamlining the debugging process. In 2026, Apache Airflow developers can efficiently transform overwhelming `pytest (DagBag)` test output into a prioritized list of distinct root causes using Atlas. This terminal-native AI agent leverages tools like `bash`, `grep`, and `todowrite` to manage the entire triage workflow, from running the suite with `uv` to formatting fixes with `ruff format`. ## Key takeaways - Atlas runs Apache Airflow `pytest (DagBag)` suites with `bash`, handling large outputs by saving full logs. - Use Atlas `grep` to group `pytest` failures by distinct root causes, not just test names, in your `dags/` folder. - Atlas `todowrite` helps track and prioritize fixes for unique Apache Airflow issues. - Make targeted code changes with Atlas `edit` and re-run specific `pytest` tests for rapid iteration. - Atlas ensures safe Apache Airflow code modifications with permission prompts and unified diff approvals. - Leverage `uv` for package management and `ruff format` for consistent code style within Atlas. ## How does Atlas run `pytest (DagBag)` tests in Apache Airflow and manage large logs? Running the full Apache Airflow test suite with `pytest (DagBag)` can produce extensive output, often exceeding 2000 lines. Atlas addresses this by using its `bash` tool to execute `uv run pytest dags/` with a generous timeout, ensuring even slow tests complete without interruption. When you instruct Atlas to run your Apache Airflow test suite, it uses the `bash` tool to execute the command, for example, `uv run pytest dags/`. This command targets your `dags/` folder, where your DAG objects and task dependencies reside, ensuring that `DagBag` import tests are included. Atlas configures `bash` with a generous timeout, specified in milliseconds, to prevent the suite from being prematurely killed if it runs slowly, a common scenario in complex Airflow environments. Crucially, Atlas's `bash` tool is designed to handle large outputs: it truncates the displayed terminal output at 2000 lines or 50 KB to maintain readability, but it always writes the complete, untruncated log to a retained file. The path to this full log file is then provided in the `...output truncated...` header, allowing you to access the entire test run details for comprehensive analysis, rather than relying on a lossy tail. This ensures that no critical failure information is lost, even when dealing with a wall of red output from a large Airflow project. ## How do I group Apache Airflow `pytest` failures by root cause with Atlas? After running your Apache Airflow `pytest (DagBag)` suite, Atlas helps you move beyond individual test names to identify distinct root causes. Instead of sifting through hundreds of lines, you can use Atlas's `grep` tool on the complete log file to group failures, often reducing a massive output to 5-10 unique issues. Triage in Apache Airflow often means distinguishing between symptoms and underlying problems. Atlas facilitates this by guiding you to group failures by their root cause rather than by individual test names, which can be misleading if many tests fail due to a single bug. Once the `pytest (DagBag)` suite has run and the complete log is saved, Atlas prompts you to use its `grep` tool. You'll apply `grep` to the full log file, identified by the path provided by the `bash` tool. For instance, you might `grep -E "AssertionError|TypeError|NameError"` or search for specific stack trace patterns or error messages that indicate a common origin. This approach is particularly effective for Airflow's `dags/` folder tests, where a single misconfigured connection or a bug in a custom operator could cascade into numerous `DagBag` import failures. By focusing on distinct error signatures, you can quickly distill a voluminous test report into a manageable list of unique problems, making the subsequent fixing process far more efficient. ## How does Atlas track and fix distinct Apache Airflow test failures? Once distinct root causes are identified from your Apache Airflow `pytest (DagBag)` output, Atlas helps you track and resolve them systematically. It uses the `todowrite` tool to create a pending list of fixes, ensuring that each of the 3-5 critical issues is addressed without being forgotten. With the distinct root causes identified, Atlas transitions you into a structured fixing workflow. For each unique issue discovered through `grep` in your Apache Airflow test logs, you'll use Atlas's `todowrite` tool to create a new entry. This entry records the specific problem, marked with a "pending" status, ensuring that every identified root cause is tracked and not overlooked. For example, if a `TypeError` in a custom operator within your `dags/` folder is causing multiple `DagBag` failures, you'd create a `todowrite` entry for that specific `TypeError`. When you're ready to address an issue, you use Atlas's `edit` tool. This allows you to make precise changes to your Airflow code, such as modifying a DAG definition or a custom operator. After making an edit, you can re-run only the affected tests using `bash`, rather than the entire suite, to quickly verify your fix. This iterative process, supported by `todowrite` for tracking and `edit` for focused changes, significantly accelerates the debugging cycle for Apache Airflow projects. ## How does Atlas ensure safe and reviewable changes to Apache Airflow code? Atlas prioritizes safety and transparency when modifying Apache Airflow code, from `dags/` to `pyproject.toml`. Every proposed change, whether a `ruff format` adjustment or a complex refactor, is presented as a unified diff for your approval, ensuring you retain full control over the 100% of the code. When working with critical Apache Airflow components like DAG definitions, custom operators, or even the `pyproject.toml` file that pins `apache-airflow`, safety is paramount. Atlas is designed with multiple layers of review and approval to prevent unintended changes. Before any tool call, such as `edit` or `ruff format`, Atlas checks against permission-gated allow, ask, and deny rules. It first drafts a plan in a read-only plan agent, asking for your confirmation before switching to a build agent to execute changes. For every file edit, Atlas computes a unified diff, clearly showing what has been added, removed, or modified. This diff is surfaced for your explicit approval before Atlas writes any changes to disk. Furthermore, Atlas snapshots file changes as git patches, allowing you to easily diff edits or roll back to previous states if necessary. This robust review process, combined with its ability to read `git` branches and status, ensures that all modifications to your Apache Airflow codebase are transparent, controlled, and fully auditable, giving you confidence in the integrity of your `dags/` and other project files. ## Steps 1. Run the Apache Airflow test suite with Atlas `bash`: Execute `uv run pytest dags/` using Atlas's `bash` tool, ensuring a generous timeout (e.g., `atlas bash --timeout 300000 "uv run pytest dags/"`) to accommodate slow `DagBag` parsing and test execution. 2. Access the complete test log: If the `bash` output indicates truncation, use Atlas's `read` tool to open the full log file path provided in the `...output truncated...` header, ensuring you have all `pytest (DagBag)` details. 3. Group failures by root cause using Atlas `grep`: Analyze the complete log file with Atlas's `grep` tool, searching for common error patterns (e.g., `atlas grep "TypeError|ValueError"` or specific stack trace lines) to identify distinct underlying issues rather than individual test failures. 4. Record distinct root causes with Atlas `todowrite`: For each unique root cause identified, create a new entry using Atlas's `todowrite` tool (e.g., `atlas todowrite "Fix TypeError in custom_operator.py"`), setting its status to pending for systematic tracking. 5. Edit Apache Airflow code with Atlas `edit`: Select a pending `todowrite` item and use Atlas's `edit` tool to modify the relevant Apache Airflow code, such as a DAG definition in `dags/` or a custom operator, to address the root cause. 6. Re-run affected tests with Atlas `bash`: After making changes, use Atlas's `bash` tool to re-run only the specific `pytest (DagBag)` tests affected by your fix, verifying the resolution quickly without executing the entire suite. 7. Format code with `ruff format` and review diff: If code changes were made, ask Atlas to run `ruff format` on the modified files and review the unified diff presented by Atlas before approving the write, ensuring code style consistency. ## FAQ ### How does Atlas handle the large output from a full Apache Airflow `pytest (DagBag)` run? Atlas's `bash` tool executes your `uv run pytest dags/` command, truncating terminal output at 2000 lines or 50 KB for readability. However, it always writes the complete, untruncated log to a retained file, providing the path in the `...output truncated...` header. You can then use Atlas's `read` tool to access the full log for comprehensive analysis of all `DagBag` import tests and other failures. ### Can Atlas help me identify the actual root cause of multiple `pytest` failures in my Apache Airflow DAGs? Yes, Atlas encourages grouping failures by root cause rather than individual test names. After running your `pytest (DagBag)` suite, you'll use Atlas's `grep` tool on the complete log file to search for common error messages, stack trace patterns, or specific exceptions (e.g., `TypeError`, `NameError`) that indicate a single underlying problem affecting multiple tests in your `dags/` folder. ### How does Atlas ensure I don't forget about a test failure I've identified in Apache Airflow? Atlas integrates a `todowrite` tool specifically for this purpose. Once you've identified a distinct root cause from your Apache Airflow `pytest (DagBag)` output, you create a `todowrite` entry for it, marking its status as pending. This ensures that each unique issue is tracked and systematically addressed, preventing critical fixes from being overlooked. ### What safety measures does Atlas have when it suggests changes to my Apache Airflow code? Atlas employs several safety mechanisms. All tool calls are permission-gated. It first drafts a plan in a read-only agent and asks for your approval before executing. For every proposed file edit, including those from `ruff format`, Atlas computes and displays a unified diff for your explicit approval before writing any changes. It also snapshots file changes as git patches for easy rollback. ### Can Atlas help me refactor Apache Airflow DAGs using the TaskFlow API? While this page focuses on test triage, Atlas is capable of refactoring. The context states Atlas can "rewrite a chain of PythonOperators using the TaskFlow API so XCom passing becomes plain return values." This demonstrates its ability to understand and modify Airflow-specific idioms beyond just testing. ### How does Atlas integrate with my existing Apache Airflow development environment, including `uv` and `ruff format`? Atlas is designed to work direct with your existing Apache Airflow toolchain. It uses its `bash` tool to execute commands like `uv run pytest dags/` for testing and `ruff format` for code formatting. Atlas can also read your `pyproject.toml` file to understand package dependencies and ensure consistency with your project's defined tools and versions. ### Does Atlas support local embedding models for code indexing in Apache Airflow projects? Yes, Atlas can build its code index using local Ollama embeddings. This means your Apache Airflow code, including sensitive DAG definitions and custom operators, remains entirely on your local machine, never leaving your environment for third-party servers, ensuring privacy and security. --- Canonical HTML: https://runatlas.sh/resources/stacks/run-the-test-suite-and-triage-failures-in-airflow Source of truth: aeo_pages row `/resources/stacks/run-the-test-suite-and-triage-failures-in-airflow` (segment: Stacks) (this file is generated from it, never hand-edited). Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.