fix(core): [Callback Errors 3] Drop failed breadcrumbs

[adinauer]

PR Stack (Callback Errors)

• fix(core): Handle callback errors #6140
• fix(core): [Callback Errors 1] Report callback failures #6141
• fix(core): [Callback Errors 2] Drop failed processor data #6142
• fix(core): [Callback Errors 3] Drop failed breadcrumbs #6143

---

📜 Description

Drops a breadcrumb when beforeBreadcrumb throws. The failed breadcrumb is not stored, decorated with exception details, or sent to scope observers.

Later breadcrumb additions continue to work because the callback reentrancy guard is released after the exception.

💡 Motivation and Context

Keeping the original breadcrumb after a filtering callback fails can retain data the callback intended to remove. Dropping it matches the fail-closed callback policy and avoids storing callback exception details on telemetry.

• refs: Align callback error handling with other SDKs #6081

💚 How did you test it?

• ./gradlew spotlessApply apiDump
• ./gradlew :sentry:test --tests io.sentry.ScopeTest --tests io.sentry.ScopesTest

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the 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.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

None.

⚠️ Merge this PR using a merge commit (not squash). Only the collection branch is squash-merged into main.

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

### Fixes

- [Callback Errors 3] Drop failed breadcrumbs ([#6143](https://github.com/getsentry/sentry-java/pull/6143))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description or adding a skip-changelog label.

Generated by 🚫 dangerJS against fa3ca45

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.57.0 (1)	release

⚙️ sentry-android Build Distribution Settings