libdatadog update to 4cfd390c

[dd-octo-sts]

Summary

Automated update of the libdatadog submodule to the latest HEAD.

	SHA
Previous	$LIBDATADOG_PINNED_SHA
New	4cfd390c26275689456a8bd7db26d37601d232d7

Full CI result: ❌ 175 job(s) failed
CI pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-php/-/pipelines/133537062

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(Claude did not produce a report — see tmp/artifacts/claude_output.txt in the CI pipeline.)

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/cc @bwoebi

[datadog-datadog-prod-us1-2]

 

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⚠️ Warnings

❌ Your PR has failed checks. Please review the issues below and take necessary action before merging.

🚦 247 Pipeline jobs failed

DataDog/apm-reliability/dd-trace-php | Extension Tea Tests: [7.0, debug-zts] — 🔧 Needs a code fix, caused by this PR

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DataDog/apm-reliability/dd-trace-php | Extension Tea Tests: [7.0, debug] — 🔧 Needs a code fix, caused by this PR

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DataDog/apm-reliability/dd-trace-php | Extension Tea Tests: [7.0, nts] — 🔧 Needs a code fix, caused by this PR

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View all 247 failed jobs.

ℹ️ Info

No other issues found (see more)

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 51.30% (-9.33%)

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[pr-commenter]

Benchmarks [ tracer ]

Benchmark execution time: 2026-08-26 04:59:51

Comparing candidate commit 3bd9d2f in PR branch bot/libdatadog-latest with baseline commit 2e85cae in branch master.

Found 2 performance improvements and 1 performance regressions! Performance is the same for 191 metrics, 0 unstable metrics.

Explanation

This is an A/B test comparing a candidate commit's performance against that of a baseline commit. Performance changes are noted in the tables below as:

• 🟩 = significantly better candidate vs. baseline
• 🟥 = significantly worse candidate vs. baseline

We compute a confidence interval (CI) over the relative difference of means between metrics from the candidate and baseline commits, considering the baseline as the reference.

If the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD), the change is considered significant.

Feel free to reach out to #apm-benchmarking-platform on Slack if you have any questions.

More details about the CI and significant changes

You can imagine this CI as a range of values that is likely to contain the true difference of means between the candidate and baseline commits.

CIs of the difference of means are often centered around 0%, because often changes are not that big:

---------------------------------(------|---^--------)-------------------------------->
                              -0.6%    0%  0.3%     +1.2%
                                 |          |        |
         lower bound of the CI --'          |        |
sample mean (center of the CI) -------------'        |
         upper bound of the CI ----------------------'

As described above, a change is considered significant if the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD).

For instance, for an execution time metric, this confidence interval indicates a significantly worse performance:

----------------------------------------|---------|---(---------^---------)---------->
                                       0%        1%  1.3%      2.2%      3.1%
                                                  |   |         |         |
       significant impact threshold --------------'   |         |         |
                      lower bound of CI --------------'         |         |
       sample mean (center of the CI) --------------------------'         |
                      upper bound of CI ----------------------------------'

scenario:MessagePackSerializationBench/benchMessagePackSerialization

• 🟩 execution_time [-7.548µs; -4.932µs] or [-6.592%; -4.308%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization-opcache

• 🟩 execution_time [-7.406µs; -4.834µs] or [-6.445%; -4.207%]

scenario:SamplingRuleMatchingBench/benchRegexMatching4

• 🟥 execution_time [+30.912ns; +103.888ns] or [+2.073%; +6.966%]

[cataphract]

Blocked by #3725