Unable to symbolicate the Acr for app crashes

Vega Open Beta Bug Reports
1

1. Summary

unable to symbolicate the Acr for app crashes

App Name: Frndly Tv

Bug Severity
Select one that applies

  • Impacts operation of app

3. Observed Behavior

  1. In Visual Studio Code, open the command palette.

  2. Enter Kepler Device Management: Symbolicate ACR.

  3. Select an ACR file using the selection box.

  4. Kepler Studio analyzes the ACR, and requires additional information based on the crash type:
    4.1 selected the jstrace
    4.2 selected the map file from the folder: App/build/private/debugging/Release/srcmap/index.bundle.map
    4.3 click on the manual , then following logs has been shown with ? marks without specifying the function name

    and when app is crashing sometimes , following logs has been detected in logs
    (NOBRIDGE) ERROR Error: Exception in HostFunction: random_device::random_device(const std::string&): device not available, js engine: hermes

4. Expected Behavior

function trace should show instead of ? marks

5. Logs or crash report

mohammadirbaaz@administrator-Latitude-3510:~/Documents/frndlyTV_git/ReactNative-App$ kepler exec acr-report -c /home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/ACR/2222#crash_1768825239_5000_5000_25608_50924133_JSThread.acr -R /home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/build/private/debugging/Release/srcmap/index.bundle.map -g js

Successfully setup virtual environment

[INFO] Running: '/home/mohammadirbaaz/kepler/sdk/0.20.3719/workspace/env/KeplerCLIDebuggingTools-2.0/runtime/x86_64-Linux/tools/gdb_scripts/../..//tools/scripts/check_acr_report_dependencies.py ’

[notice] A new release of pip is available: 24.1.2 → 25.3

[notice] To update, run: python3 -m pip install --upgrade pip

[INFO] Running: ‘/home/kepler/sdk/0.20.3719/workspace/env/KeplerCLIDebuggingTools-2.0/runtime/x86_64-Linux/tools/gdb_scripts/../..//tools/scripts/js_symbolicate.py /home/Documents/frndlyTV_git/ReactNative-App/ACR/2222#crash_1768825239_5000_5000_25608_50924133_JSThread.acr /home/Documents/frndlyTV_git/ReactNative-App/build/private/debugging/Release/srcmap/index.bundle.map “” acr_workdir-c8d26ddf js’

2026-01-19 17:54:43 WARNING [js_symbolicate] -

WARNING: If you are trying to symbolicate an older ACR file that

            has frames that do not contain hash-bundle-ids, you may either not get those frame symbolicated or get the wrong info. 

            Please ensure that the path to the correct source map is passed into the -R option. If you are passing a source map directory

            and source maps without hashes are present, frames corresponding to those source maps will not be symbolicated.  

            If you need these to be symbolicated, please provide the path to the correct source map to the -R option.

            Manual symbolication or Crashboard"s cloud symbolication are available options.

[INFO] JS Stacktrace

JSThread thread ID: 19

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:5492:oldProps)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:5611:current)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:7164:current)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:7154:unitOfWork)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:7145:workInProgress)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:7127:null)

at ? (/home/mohammadirbaaz/Documents/frndlyTV_git/ReactNative-App/node_modules/@amzn/react-native-kepler/Libraries/Renderer/implementations/ReactFabric-prod.js:6823:root)

at ? (native)

at ? (native)

2222#crash_1768825239_5000_5000_25608_50924133_JSThread.acr (476.5 KB)

6. Environment

Please fill out the fields related to your bug below:

  • SDK Version: 0.20.3719
  • OS Information
    NAME=“OS”
    OE_VERSION=“4.0.0”
    OS_MAJOR_VERSION=“1”
    OS_MINOR_VERSION=“1”
    RELEASE_ID=“14”
    OS_VERSION=“1.1”
    BRANCH_CODE=“TV Ship day60”
    BUILD_DESC=“OS 1.1 (TV Ship day60/4454)”
    BUILD_FINGERPRINT=“4.0.198430.0(3072cab629675a74)/4454N:user-external/release-keys”
    BUILD_VARIANT=“user-external”
    BUILD_TAGS=“release-keys”
    BUILD_DATE=“Sat Dec 20 04:05:59 UTC 2025”
    BUILD_TIMESTAMP=“1766203559”
    VERSION_NUMBER=“1401010445450”

3

Hello @YuppTV

We are looking into this issue. Kindly allow us some time to look into this in depth and update you.

Warm Regards,
Ivy

4

Hi @Ivy_Mahajan, is there any update?

5

Hi @YuppTV

Initial investigation:

- Version Mismatch: The app binary was compiled with SDK 0.20.3719 but may be running on a device that expects the latest SDK version (0.22.5600)

- Hermes Engine Update: SDK 0.22.5600 may include changes to Hermes engine version or random_device. Also in the description it’s mentioned Kepler Device Management: Symbolicate ACR while it has been changed to Vega Device Management: Symbolicate ACR {} . The updated React Native Kepler libraries may have caused the Source Map format changes or hash-bundle-id schemes, which explains why symbolication shows ‘?’ marks.

We are still working on it. Will update you soon.

Warm regards,
Ivy

6

Hi @YuppTV
Would you please share if you used the release or debug variation build?
Your JS stack trace shows:

at ? (/home/mohammadirbaaz/Documents/.../build/lib/rn-bundles/Release/index.bundle:6778:210)

The path shows:

Release/index.bundle

→ This is a Release build ACR.

The Fix:

You’re providing the wrong source map path. The ACR expects:

build/lib/rn-bundles/Release/<hash-id>.bundle.map

But you’re providing:

build/private/debugging/Release/srcmap/index.bundle.map

Correct Command:

kepler exec acr-report
  -c <your-acr-file> \
  -R ~/Documents/frndlyTV_git/ReactNative-App/build/lib/rn-bundles/Release/<hash-id>.bundle.map
  -g js

Why This Happens:

Release builds generate the bundle and source map in

build/lib/rn-bundles/Release/

, not in

build/private/debugging/

. The debugging path is for Debug builds only.

Verification:

Check that bundle map exists in:

ls -la ~/Documents/frndlyTV_git/ReactNative-App/build/lib/rn-bundles/Release

If it doesn’t exist, rebuild your Release variant:

react-native build-vega
7

Hi @Parisa_Hemmati ,
We observed that our local build-kepler Release builds are not generating any source maps (index.bundle.map or hashed .bundle.map). Only index.bundle and index.hermes.bundle are produced.Because of this, we cannot obtain a matching source map for the ACR, which prevents JS symbolication. Could you please confirm how to enable source map generation for Kepler Release builds or provide the corresponding source map for this ACR?
for release build:
npm run “NODE_OPTIONS=‘–max-old-space-size=4096’ react-native build-kepler --build-type Release --build-number 120”,

ls -la ~/Documents/frndlyTV_git/ReactNative-App/build/lib/rn-bundles/Release
total 28648
drwxrwxr-x 3 mohammadirbaaz mohammadirbaaz 4096 Jan 29 18:15 .
drwxrwxr-x 3 mohammadirbaaz mohammadirbaaz 4096 Jan 29 16:42 ..
drwxrwxr-x 4 mohammadirbaaz mohammadirbaaz 4096 Jan 29 16:43 assets
-rw-rw-r-- 1 mohammadirbaaz mohammadirbaaz 17046828 Jan 29 18:14 index.bundle
-rw-rw-r-- 1 mohammadirbaaz mohammadirbaaz 12275507 Jan 29 18:15 index.hermes.bundle

8

Hi @Parisa_Hemmati ,
we have update sdk to latest version vega 0.22.5875, but still acr symbolication is not happening,

9

@YuppTV
Does your build generate any source map in the mentioned directory?

10

Hi @Parisa_Hemmati ,
Yes, a hashed <hashId>.bundle.map is generated under build/lib/rn-bundles/Release/, but not for every Release build.

Even when automatic symbolication is used with the hashed source map, several stack frames still show ? for function names.

Is this expected behavior for Vega Release builds, or is additional configuration required for full JS symbolication?

Thank you.

11

Currently each release build will generate a new hash map w/o replacing the previous one, make sure you are using the correct hash map corresponding to the ACR release build for symbolication. Also please attach your crash report here so we can further investigate the issue.
Thanks