feat: do not report error stack for status code errors

[hannahkm]

What does this PR do?

• Creates a new tag, ErrorNoStackTrace, to report errors without capturing the stack trace for our UI.
• Better aligns our error tags with Error Tracking. This includes moving error.stack to error.handling_stack, moving error.details into error.stack, and deprecating error.details.

Motivation

We were creating errors and reporting the stack for status code errors. For new error stack features (#3709), this causes us to create two error stacks: one starting from SetTag and one started from error creation. To avoid this, and also because reporting these error stacks is superfluous, we want to prevent reporting these stacks to hide them from our UI.

For information on what each tag represents, refer to this (internal) page.

IMPORTANT: this might be considered a breaking change for Error Tracking. Please check with the ET team before releasing this feature.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• New code is free of linting errors. You can check this by running ./scripts/lint.sh locally.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.

Unsure? Have a question? Request a review!

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-09-24 14:35:03

Comparing candidate commit 4fefb03 in PR branch hannahkm/new-error-tag with baseline commit e2c8d45 in branch main.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 2 metrics, 0 unstable metrics.

scenario:BenchmarkSetTagStringPtr-24

• 🟥 execution_time [+5.953ns; +9.007ns] or [+4.261%; +6.447%]

[kakkoyun]

We are adding these two new tags, what are the implications on the ingestion side? Especially for error tracking?

[hannahkm]

The new tags will change the behavior of error tags on spans; handling_stack should already be handled from the error tracking side, but we just haven't been taking advantage of it earlier. The fingerprints of spans will change after we release this PR, so we should give them a heads-up before so that they can adjust in the backend.

[kakkoyun]

Thanks for the explanation ☺️

[hannahkm]

/merge

[dd-devflow-routing-codex]

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2025-09-24 18:35:08 UTC ⚠️ MergeQueue: This merge request was unqueued

devflow unqueued this merge request: It did not become mergeable within the expected time

[datadog-official]

⚠️ Tests

⚠️ Warnings

❄️ 1 New flaky test detected

TestWrapConsumerGroupHandler from github.com/DataDog/dd-trace-go/contrib/IBM/sarama/v2 (Datadog) (✨ Fix with BitsAI)

Failed

=== RUN   TestWrapConsumerGroupHandler
2025/09/24 14:48:13 Sarama consumer up and running!...
    consumer_group_test.go:146: Message claimed: value = test 1, timestamp = 2025-09-24 14:48:13.724 +0000 UTC, topic = IBM_sarama_TestWrapConsumerGroupHandler
    consumer_group_test.go:88: 
        	Error Trace:	/home/runner/work/dd-trace-go/dd-trace-go/contrib/IBM/sarama/consumer_group_test.go:88
        	Error:      	"[
        	            	name: kafka.produce
        	            	tags: map[string]interface {}{"_dd.base_service":"", "_dd.p.tid":"68d404ad00000000", "_dd.profiling.enabled":0, "_dd.top_level":1, "component":"IBM/sarama", "language":"go", "messaging.destination.name":"IBM_sarama_TestWrapConsumerGroupHandler", "messaging.kafka.partition":0, "messaging.system":"kafka", "offset":0, "resource.name":"Produce Topic IBM_sarama_TestWrapConsumerGroupHandler", "service.name":"kafka", "span.kind":"producer", "span.name":"kafka.produce", "span.type":"queue"}
...

ℹ️ Info

🧪 All tests passed

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 4fefb03 | Docs | Was this helpful? Give us feedback!}

[hannahkm]

/merge

[dd-devflow-routing-codex]

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2025-09-24 18:41:37 UTC ℹ️ Start processing command /merge

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2025-09-24 18:41:42 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 18m (p90).

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2025-09-24 18:56:35 UTC ℹ️ MergeQueue: This merge request was merged