Firebase & App Integrity

Crashlytics Mapping Files: Match the Exact Release Variant

Crashlytics needs the R8 mapping associated with the exact release to reconstruct obfuscated Java/Kotlin frames. A mapping upload from a different flavor or rebuild can make reports incomplete or misleading.

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Bind mapping to the release artifact

Archive package ID, version code, build identifier, artifact hash and mapping together in CI. Do not rely on a developer's latest local mapping.txt after an incident.

The Crashlytics deobfuscation guide explains build integration and mapping handling for supported Android setups.

Verify the intended upload task

Check that the plugin is applied to the app module and that mapping upload is enabled for the distributed optimized variant. Task names and configuration should follow the installed plugin version rather than an old hard-coded script.

Failure Inspect
Upload task fails Network, credentials/configuration and plugin compatibility
No mapping generated Whether that variant is optimized
Report remains obfuscated Correct app/build association and upload completion
Native frames unresolved Native symbols, not Java mapping

Keep local retracing as an independent check

Use Retrace with the preserved mapping and a raw trace from that release. If local retracing works but the dashboard does not, investigate upload and association rather than changing keep rules immediately.

If both are wrong, first verify that the mapping belongs to the crash build.

Do not disable upload to hide a release failure

A build that succeeds only after removing a failing mapping task may ship without usable crash diagnostics. Resolve the cause or document the operational limitation explicitly before release.

Keep secrets out of build logs when diagnosing network or configuration failures.

Confirm with a controlled optimized crash

Install the actual test release, trigger a known crash and inspect readable frames in the intended Firebase app. APKLint can support trace interpretation and build review, but it cannot validate a private mapping upload. The completion evidence is a correctly associated, readable report from the exact distributed build.

Sources and further reading

  1. Firebase: Get readable crash reports
  2. Android Developers: Retrace

Reference review: 22 September 2026. Examples illustrate the workflow; check your installed versions, release artifact and account-specific Console requirements before applying them. This guide is not a claim that APKLint executed your project or verified your private account.

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