fix(profiling): Fix app start transaction profile timestamp offset by antonis · Pull Request #5962 · getsentry/sentry-react-native

antonis · 2026-04-07T09:58:34Z

📢 Type of change

Bugfix
New feature
Enhancement
Refactoring

📜 Description

Uses the actual profiling start timestamp for the profile's timestamp field instead of the adjusted event.start_timestamp.

For app start transactions, the SDK adjusts the transaction's start_timestamp backward to the app start time. However, profile samples use elapsed_since_start_ns relative to when profiling actually started (JS VM start), not the app start time. This mismatch caused the profile to appear misaligned in the Sentry UI.

Changes:

Added profilingStartTimestampNs field to HermesProfileEvent and AndroidCombinedProfileEvent types
stopProfiling now stores the profiling start timestamp on the returned profile event
enrichCombinedProfileWithEventContext and enrichAndroidProfileWithEventContext prefer the stored profiling start timestamp over event.start_timestamp
The internal field is stripped before serialization via destructuring

💡 Motivation and Context

Fixes #4511

When an app start transaction has its start time adjusted, the profile timestamp was incorrectly set to the app start time, while profile samples were relative to the JS VM start. This caused a visual offset in the Sentry profiling UI.

Relay does not validate the profile timestamp against the transaction start_timestamp, so this change is safe from the ingestion side.

💚 How did you test it?

All existing tests pass (196 tests)
Build succeeds
For non-app-start transactions: no behavior change (profiling start ≈ transaction start)
For app start transactions: profile timestamp now correctly reflects when profiling started

📝 Checklist

I added tests to verify changes
No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled
I updated the docs if needed.
I updated the wizard if needed.
All tests passing
No breaking changes

🔮 Next steps

Use the actual profiling start timestamp for the profile's timestamp field instead of the adjusted transaction start_timestamp. For app start transactions, the transaction start is adjusted backward to the app start time, but the profile samples are relative to when profiling actually started (JS VM start). This caused a misalignment in the Sentry UI. Fixes #4511 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

github-actions · 2026-04-07T09:58:58Z

Semver Impact of This PR

⚪ None (no version bump detected)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

fix(profiling): Fix app start transaction profile timestamp offset by antonis in #5962

fix(android): Use componentStack as fallback for missing error stack traces by antonis in #5965
chore(deps): bump addressable from 2.8.7 to 2.9.0 in /samples/react-native-macos by dependabot in #5967
chore(deps): bump addressable from 2.8.7 to 2.9.0 in /samples/react-native by dependabot in #5966
fix(ios): Add SENTRY_PROJECT_ROOT env var for monorepo support by antonis in #5961
feat(ios): Add attachAllThreads option by antonis in #5960
fix(core): Lazy-load Metro internal modules to prevent Expo 55 import errors by lucas-zimerman in #5958
chore(deps): update Cocoa SDK to v9.9.0 by github-actions in #5956
chore(deps): update Maestro to v2.4.0 by github-actions in #5955
Feat: Fallback to stacktrace parsing by lucas-zimerman in #5946
fix(ci): Bump Node to 22 in size-analysis and testflight workflows by antonis in #5954
feat(playground): Open Sentry in desktop browser from Expo apps by antonis in #5947
chore(core): Bump sample app to React Native 0.84.1 by antonis in #5941
Size analysis for React Native SDK by alwx in #5949
chore(deps): bump lodash from 4.17.23 to 4.18.1 by dependabot in #5953
chore(deps): bump yauzl to ^3.2.1 by antonis in #5950
chore(deps): bump brace-expansion to ^2.0.3 by antonis in #5951
chore(deps): bump @xmldom/xmldom to fix XML injection by antonis in #5952

_{🤖 This preview updates automatically when you update the PR.}

CHANGELOG.md

Add unit tests for enrichCombinedProfileWithEventContext and enrichAndroidProfileWithEventContext verifying that: - profilingStartTimestampNs is used for the profile timestamp when set - Falls back to event.start_timestamp when not set - profilingStartTimestampNs is stripped from serialized output Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

sentry · 2026-04-07T10:22:52Z

Sentry Build Distribution

App Name	App ID	Version	Configuration	Install Page
Sentry RN	io.sentry.reactnative.sample	8.7.0 (82)	Release	Install Build

Configure sentry-react-native build distribution settings

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lucas-zimerman

LGTM!

github-actions · 2026-04-09T09:39:19Z

Android (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	406.88 ms	430.90 ms	24.02 ms
Size	43.75 MiB	48.08 MiB	4.33 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`df5d108`+dirty	527.06 ms	603.58 ms	76.52 ms
`2c735cc`+dirty	414.09 ms	438.47 ms	24.38 ms
`a50b33d`+dirty	500.81 ms	532.11 ms	31.30 ms
`3817909`+dirty	406.67 ms	416.58 ms	9.91 ms
`5c1e987`+dirty	423.52 ms	471.64 ms	48.12 ms
`4953e94`+dirty	442.02 ms	456.52 ms	14.50 ms

App size

Revision	Plain	With Sentry	Diff
`df5d108`+dirty	43.75 MiB	48.08 MiB	4.33 MiB
`2c735cc`+dirty	43.75 MiB	48.08 MiB	4.33 MiB
`a50b33d`+dirty	43.75 MiB	48.08 MiB	4.33 MiB
`3817909`+dirty	43.75 MiB	48.08 MiB	4.33 MiB
`5c1e987`+dirty	43.75 MiB	48.08 MiB	4.33 MiB
`4953e94`+dirty	43.75 MiB	48.08 MiB	4.33 MiB

github-actions · 2026-04-09T09:58:36Z

iOS (legacy) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1210.93 ms	1212.39 ms	1.46 ms
Size	3.38 MiB	4.74 MiB	1.35 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`a50b33d`+dirty	1197.74 ms	1197.17 ms	-0.57 ms
`3817909`+dirty	1183.90 ms	1187.50 ms	3.60 ms
`5c1e987`+dirty	1204.30 ms	1222.15 ms	17.85 ms
`2c735cc`+dirty	1229.67 ms	1221.50 ms	-8.17 ms
`4953e94`+dirty	1212.06 ms	1214.83 ms	2.77 ms
`df5d108`+dirty	1225.90 ms	1220.14 ms	-5.76 ms

App size

Revision	Plain	With Sentry	Diff
`a50b33d`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`3817909`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`5c1e987`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`2c735cc`+dirty	3.38 MiB	4.74 MiB	1.35 MiB
`4953e94`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`df5d108`+dirty	3.38 MiB	4.73 MiB	1.35 MiB

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 73ea8a5. Configure here.}

cursor · 2026-04-09T10:10:45Z

CHANGELOG.md

+- Fix app start transaction profile offset by using the actual profiling start timestamp instead of the adjusted app start time ([#5962](https://github.com/getsentry/sentry-react-native/issues/5962))
+=======
 - Use React `componentStack` as fallback when error has no stack trace on Android ([#5965](https://github.com/getsentry/sentry-react-native/pull/5965)
+>>>>>>> main


Unresolved merge conflict markers in CHANGELOG

High Severity

Unresolved git merge conflict markers (<<<<<<<, =======, >>>>>>>) were accidentally committed in CHANGELOG.md. This breaks the Markdown rendering and drops the existing componentStack changelog entry from its proper location, as both changelog entries need to appear without conflict markers.

^{Triggered by project rule: PR Review Guidelines for Cursor Bot}

^{Reviewed by Cursor Bugbot for commit 73ea8a5. Configure here.}

sentry · 2026-04-09T10:10:52Z

CHANGELOG.md

+<<<<<<< fix/profile-app-start-timestamp-offset
+- Fix app start transaction profile offset by using the actual profiling start timestamp instead of the adjusted app start time ([#5962](https://github.com/getsentry/sentry-react-native/issues/5962))
+=======
 - Use React `componentStack` as fallback when error has no stack trace on Android ([#5965](https://github.com/getsentry/sentry-react-native/pull/5965)
+>>>>>>> main


Bug: The CHANGELOG.md file contains unresolved git merge conflict markers, which will break the release process.
_{Severity: HIGH}

Suggested Fix

Resolve the merge conflict in CHANGELOG.md. Remove the git conflict markers (<<<<<<<, =======, >>>>>>>) and combine the changelog entries from both branches correctly.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not valid. Location: CHANGELOG.md#L13-L17 Potential issue: The `CHANGELOG.md` file contains unresolved git merge conflict markers (`<<<<<<<`, `=======`, `>>>>>>>`) that were committed to the codebase. While this does not cause a runtime error in the application, it will break the release tooling which automatically parses the changelog. This failure in the release automation will prevent new versions of the software from being released.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

github-actions · 2026-04-09T10:40:03Z

iOS (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1221.28 ms	1223.07 ms	1.79 ms
Size	3.38 MiB	4.74 MiB	1.35 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`a50b33d`+dirty	1207.11 ms	1212.10 ms	5.00 ms
`3817909`+dirty	1210.76 ms	1215.64 ms	4.89 ms
`5c1e987`+dirty	1208.43 ms	1220.72 ms	12.29 ms
`2c735cc`+dirty	1223.33 ms	1224.38 ms	1.04 ms
`4953e94`+dirty	1217.41 ms	1223.53 ms	6.12 ms
`df5d108`+dirty	1207.34 ms	1210.50 ms	3.16 ms

App size

Revision	Plain	With Sentry	Diff
`a50b33d`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`3817909`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`5c1e987`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`2c735cc`+dirty	3.38 MiB	4.74 MiB	1.35 MiB
`4953e94`+dirty	3.38 MiB	4.73 MiB	1.35 MiB
`df5d108`+dirty	3.38 MiB	4.73 MiB	1.35 MiB

github-actions · 2026-04-09T10:40:04Z

Android (new) Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	405.56 ms	422.78 ms	17.22 ms
Size	43.94 MiB	48.94 MiB	5.00 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
`df5d108`+dirty	434.82 ms	447.39 ms	12.57 ms
`2c735cc`+dirty	435.20 ms	459.48 ms	24.28 ms
`a50b33d`+dirty	353.21 ms	398.48 ms	45.27 ms
`3817909`+dirty	357.52 ms	391.52 ms	34.00 ms
`5c1e987`+dirty	444.71 ms	475.13 ms	30.42 ms
`4953e94`+dirty	398.80 ms	431.81 ms	33.01 ms

App size

Revision	Plain	With Sentry	Diff
`df5d108`+dirty	43.94 MiB	48.94 MiB	5.00 MiB
`2c735cc`+dirty	43.94 MiB	48.94 MiB	5.00 MiB
`a50b33d`+dirty	43.94 MiB	48.94 MiB	5.00 MiB
`3817909`+dirty	43.94 MiB	48.94 MiB	5.00 MiB
`5c1e987`+dirty	43.94 MiB	48.94 MiB	5.00 MiB
`4953e94`+dirty	43.94 MiB	48.94 MiB	5.00 MiB

antonis commented Apr 7, 2026

View reviewed changes

CHANGELOG.md Outdated Show resolved Hide resolved

antonis and others added 2 commits April 7, 2026 12:00

fix changelog

fef6f6c

style(profiling): Fix formatting

a784129

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

antonis marked this pull request as ready for review April 7, 2026 10:51

antonis requested review from alwx and lucas-zimerman as code owners April 7, 2026 10:51

Merge branch 'main' into fix/profile-app-start-timestamp-offset

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lucas-zimerman approved these changes Apr 8, 2026

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Merge branch 'main' into fix/profile-app-start-timestamp-offset

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lucas-zimerman added the ready-to-merge Triggers the full CI test suite label Apr 9, 2026

Merge branch 'main' into fix/profile-app-start-timestamp-offset

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📢 Type of change

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📝 Checklist

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iOS (new) Performance metrics 🚀

Baseline results on branch: main

Startup times

App size

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Android (new) Performance metrics 🚀

Baseline results on branch: main

Startup times

App size

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