fix(task-sdk): include error details in ServerResponseError string representation

[YoannAbriel]

Problem

When ServerResponseError is raised and propagates up the call stack without being explicitly caught and handled, error details are lost. Logs show only:

airflow.sdk.api.client.ServerResponseError: Server returned error

...without any information about what actually went wrong. This makes debugging significantly harder, especially for TaskInstanceOperations calls where the exception is not caught and re-logged with e.detail.

Root Cause

ServerResponseError stores error details in its detail attribute, but the __str__() method (inherited from httpx.HTTPStatusError) only returns the base message. When the exception is logged via traceback or str(err), the detail is silently dropped.

Some call sites (e.g., VariableOperations) explicitly catch ServerResponseError and log e.detail, but many others (e.g., TaskInstanceOperations.start()) let it propagate, losing the detail entirely.

Fix

Added a __str__() override to ServerResponseError that appends the detail attribute when present. This ensures error details are always visible in logs and tracebacks, regardless of how the exception is caught.

Before:

ServerResponseError: Server returned error

After:

ServerResponseError: Server returned error
Detail: {'reason': 'invalid_state', 'message': 'TI was not in the running state'}

Verified with unit tests. No external service access needed.

Closes: #57961

---

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

• Yes — Claude Code (Opus 4, claude-opus-4-6)

Generated-by: Claude Code (Opus 4, claude-opus-4-6) following the guidelines

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• Read the Pull Request Guidelines for more information.

[SameerMesiah97]

Needs some adjustments. Please see my comments.

[SameerMesiah97]

Right now def __str__ assumes that the detail attribute is always present in ServerResponseError. As evidenced by failing CI, this is not always true. Try adding doing something like this instead:

def __str__(self) -> str:
    base = super().__str__()
    detail = getattr(self, "detail", None)

    if detail is not None:
        return f"{base}\nDetail: {detail}"

    return base

Using if detail is not None instead of if self.detail or if not self.detail has the added benefit of including falsy values like {} or "", which might be considered meaningful API messages.

[YoannAbriel]

Fixed — using getattr(self, 'detail', None) now.

[SameerMesiah97]

This test appears to covering scenarios where detail exists but is None. I would add another test for cases where the detail attribute does not exist. I would ensure that both of these tests (the current one for detail = None and the new one for detail not present which you may add) communicate their intent precisely in their naming, docstrings and comments.

[YoannAbriel]

Added test_server_response_error_str_missing_detail_attr that creates a bare instance without the attribute.

[potiuk]

@YoannAbriel A few things need addressing before review — see our Pull Request quality criteria.

• ❌ Pre-commit / static checks: Failing: CI image checks / Static checks. Run prek run --from-ref main locally to find and fix issues. See Pre-commit / static checks docs.

Note: Your branch is 251 commits behind main. Please rebase and push again to get up-to-date CI results.

No rush.

---

Note: This comment was drafted by an AI-assisted triage tool and may contain mistakes. Once you have addressed the points above, an Apache Airflow maintainer — a real person — will take the next look at your PR. We use this two-stage triage process so that our maintainers' limited time is spent where it matters most: the conversation with you.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Improves debuggability of ServerResponseError by ensuring its string representation includes server-provided error details when available, so tracebacks/logs retain actionable context.

Changes:

• Override ServerResponseError.__str__() to append detail to the base message.
• Add unit tests covering __str__() behavior with dict detail, string detail, and missing detail attribute.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
task-sdk/src/airflow/sdk/api/client.py	Adds __str__() override to include detail in the exception string.
task-sdk/tests/task_sdk/api/test_client.py	Adds tests validating the new __str__() behavior across detail variants.

[Copilot]

The if detail := ... check is truthiness-based, so empty-but-present details (e.g., {} / []) will be omitted even though detail exists. If the intent is to include details whenever the attribute is present (and not None), assign first and check detail is not None (or alternatively check hasattr(self, 'detail') and self.detail is not None).

Suggested change

	if detail := getattr(self, "detail", None):
	detail = getattr(self, "detail", None)
	if detail is not None:

[Copilot]

This test relies on constructing ServerResponseError via __new__ without initializing the underlying httpx.HTTPStatusError state. That makes the test brittle against future httpx changes (e.g., if HTTPStatusError.__str__() starts requiring request/response). A more robust approach is to create a real ServerResponseError instance with minimal request/response, then remove/clear the detail attribute (e.g., delete it from __dict__) and assert str(err) does not include the Detail: section.

Suggested change

	err = ServerResponseError.__new__(ServerResponseError)
	err.args = ("Server returned error",)
	responses = [
	httpx.Response(
	409,
	json={"detail": {"reason": "invalid_state", "message": "TI was not in the running state"}},
	)
	]
	client = make_client_w_responses(responses)
	with pytest.raises(ServerResponseError) as exc_info:
	client.get("http://error")
	err = exc_info.value
	if "detail" in err.__dict__:
	del err.__dict__["detail"]

[vatsrahul1001]

@YoannAbriel can you address and resolve all open comments