[hussein-awala]

Summary

Use httpx2 throughout the Dag processor Execution API client and its tests, matching the Task SDK base client migrated in #73116. Imports and references use httpx2 explicitly, without an alias.

This fixes both mypy-airflow-core override errors (_update_auth and request) and the runtime mismatch: httpx exception handlers do not catch httpx2 errors, and httpx.Timeout objects are incompatible with the new client. Those failures affect credential renewal, registration retirement, and closed-Job handling.

Why #73116 did not catch this

The two changes landed independently:

• Migrate Task SDK to httpx2 #73116's final head was b312d3df05ecc229a8fcc2106b252cfa2ef459d4. Neither airflow-core/src/airflow/dag_processing/api_client.py nor its test file exists in that tree. Its visible successful AMD CI run started on October 13, before the new processor client merged.
• Add scoped Execution API access for Dag processors #74370 introduced the processor client and merged as a73ffaedbf on October 14 at 07:40 UTC, using the then-current httpx SDK client.
• Migrate Task SDK to httpx2 #73116 merged as 63f5845dd2 at 09:27 UTC that day, changing the SDK base client to httpx2 without migrating the newly added subclass.

The passing pre-merge checks therefore predated this incompatible combination. This is an integration gap between independently validated changes, not an error mypy is unable to detect. The import ban added by #73116 is scoped to task-sdk/pyproject.toml; it does not cover this airflow-core subclass. Git history establishes the branch contents and merge ordering; individual CI job logs were not available through the public checks view.

Validation

• Reproduced exactly two mypy-airflow-core errors before the production fix; the hook now passes, including during commit. No mypy suppression or hook exclusion was added.
• Updated the existing tests to use httpx2 responses and transport first: 29 failed, 61 passed with the unfixed production client. After the fix: 90 passed.
• CI then exposed five failures in the separate HTTP integration test file, which still used httpx transports and exception assertions. Reproduced locally as 5 failed, 3 passed, then migrated those references to httpx2 as well.
• Targeted validation after that correction: 98 passed on SQLite across both client test files; 8 passed on PostgreSQL and 8 passed on MySQL for the HTTP integration file. After rebasing onto current main, the 98 SQLite tests, regular checks (including mypy), and applicable manual checks passed again. The lowest-dependency CI rerun is still pending.
• Regular static checks and applicable manual checks passed. Manual checks excluded only the three long-running/opt-in hooks documented in the contribution workflow.
• Selected core non-database suites on Python 3.11: 5,345 passed, 11 skipped, 2 xfailed.
• breeze build-docs apache-airflow: passed.
• Selected SQLite database suites were attempted but the invocation hit its eight-minute execution limit before all suites completed. This is incomplete validation, not a passing result.

Related: #73116, #74370, #74244. The broader core migration in draft #74244 currently does not modify these Dag processor files; this is a targeted fix for the already-merged SDK migration.

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Was generative AI tooling used to co-author this PR?

• Yes — Pi coding agent 1.1.0 (OpenAI)

Generated-by: Pi coding agent 1.1.0 (OpenAI) following the guidelines

[zach-overflow]

LGTM and thank you! Also, thanks for adding the detailed analysis of the commit timelines in the PR description.

[pierrejeambrun]

Thanks

[github-actions]

Backport failed to create: v3-4-test. View the failure log Run details

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
❌	v3-4-test

You can attempt to backport this manually by running:

cherry_picker 6a91a17 v3-4-test

This should apply the commit to the v3-4-test branch and leave the commit in conflict state marking
the files that need manual conflict resolution.

After you have resolved the conflicts, you can continue the backport process by running:

cherry_picker --continue

If you don't have cherry-picker installed, see the installation guide.