libdatadog update to 7f3b16fe

[dd-octo-sts]

Summary

Automated update of the libdatadog submodule to the latest HEAD.

	SHA
Previous	$LIBDATADOG_PINNED_SHA
New	7f3b16fe1b4bfc2a016ef869459e915ee02d6d6a

Full CI result: ❌ 143 job(s) failed
CI pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/dd-trace-php/-/pipelines/142270926

---

libdatadog Integration Report

libdatadog SHA: 7f3b16fe1b4bfc2a016ef869459e915ee02d6d6a
Analysis date: 2026-10-04

Overall status

⚠️ Adapted (API changes fixed)

The change is a build-manifest change, not a Rust API change. No compiler was
available here, so the fix has not been checked with a build. Cargo stopped
before compiling any code, so the CI logs could not show compile errors behind
the manifest error. I reviewed the new libdatadog commits by hand and found
none that need source changes on our side (see below).

Build & test summary

143 jobs failed in pipeline 142270926, across the shared, profiler and appsec
sub-pipelines:

• shared: ZAI Shared Tests, Zend Abstract Interface Tests (all PHP versions
  and variants)
• profiler: PHP language tests, Cargo test, Clippy, profiling tests (centos-7
  and alpine)
• appsec: helper-rust build/test/coverage, appsec integration tests
  (including SSI)

All 48 captured traces fail at the same point. The first Cargo invocation
fails to load the workspace:

failed to parse manifest at `.../libdatadog/libdd-data-pipeline/Cargo.toml`
Caused by:
  error inheriting `serde_ignored` from workspace root manifest's
  `workspace.dependencies.serde_ignored`
Caused by:
  `dependency.serde_ignored` was not found in `workspace.dependencies`

The other 95 failed jobs have no trace. All of them run Cargo inside the
dd-trace-php workspace (they build datadog-php, the sidecar or the helper),
so they almost certainly fail on the same error. That is an inference: I had
no logs for those jobs to confirm it.

Root cause. libdatadog crates are built as members of the dd-trace-php
root workspace. Their foo.workspace = true dependencies therefore resolve
against [workspace.dependencies] in our Cargo.toml, which mirrors
libdatadog's table. libdatadog commit 804093337 ("fix(data-pipeline)!:
revert changes that made /info un-parsable", #2586) added a new
serde_ignored dependency to libdd-data-pipeline, used as a
dev-dependency. It was added to libdatadog's workspace table but not to ours.
Cargo resolves every manifest in the workspace, dev-dependencies included,
before it builds anything, so every Cargo invocation fails.

Non-trivial changes made

• Cargo.toml ([workspace.dependencies]):
  • Added serde_ignored = { version = "0.1.14", default-features = false },
    copied from libdatadog/Cargo.toml. This fixes the error above.
  • Raised async-trait from "0.1" to "0.1.85" to match libdatadog's
    table (libdatadog commits e35a4f9ba / cbe1b7292). This keeps the
    mirror in sync; it is not strictly needed to build.

I did not hand-edit Cargo.lock. CI does not run Cargo with
--locked/--frozen, so Cargo will add serde_ignored 0.1.14 to the lock
file itself. If you want the lock file committed in sync, run
cargo update -p serde_ignored (or any build) once locally.

Review of the other new libdatadog commits

The last adapted pin was in #4259, which covered e8c680a7e (the rate
limiter change). These are the commits since then:

Commit	Change	Impact on dd-trace-php
804093337	/info schema revert, new serde_ignored dependency	Fixed above. The AgentInfoStruct fields read in components-rs/agent_info.rs are unchanged. Only AgentObfuscationConfig changed, and we don't use it.
ab1c67af6	New OTLP resource attributes (_dd.sdk.otlp_export, datadog.sdk.semantics)	Internal to the trace-utils encoder; no public API change we use.
b1d377615	spawn_worker trampoline runs under the host loader	Adds a build.rs (path build-dependency cc_utils) and an opt-in feature trampoline-host-loader. No change needed in our manifests.
e35a4f9ba	async-trait version bump	Mirrored above.
4c1e1ef16, 7f3b16fe1	Release merges (crate version bumps)	We use path dependencies without version requirements, so nothing to change.
e8cdc8587, 38d53e4f6, e5c044566, 188a1f3b0	Examples and CI only	None.

Identified libdatadog issues

None identified. The failure comes from how dd-trace-php is set up: we
mirror libdatadog's [workspace.dependencies] by hand. It is not a libdatadog
bug.

A possible follow-up: CI could check that every key in libdatadog's
[workspace.dependencies] also exists in the root Cargo.toml. That would
catch this kind of drift with a clearer error.

Flaky / ignored failures

None. All 143 failures are explained by the single manifest error above.

---

/cc @bwoebi

[datadog-prod-us1-5]

✅ All CI checks and tests passed.

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 68.38% (-0.04%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 00b7177 | Docs | View more details | Give us feedback!}

[pr-commenter]

Benchmarks [ tracer ]

Benchmark execution time: 2026-10-02 03:52:16

Comparing candidate commit 541edf5 in PR branch bot/libdatadog-latest with baseline commit a768e59 in branch master.

📊 Benchmarking dashboard

Found 0 performance improvements and 0 performance regressions! Performance is the same for 194 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 ----------------------------------'