Recorder throws Unknown St13runtime_error error (aka std::runtime_error) in production on iOS

[ahmed-sudowrite]

Before submitting a new issue

• I tested using the latest version of the library, as the bug might be already fixed.
• I tested using a supported version of react native.
• I checked for possible duplicate issues, with possible answers.

Bug summary

I've just rolled out an app that makes heavy use of this library, and my employer is gearing up for a big launch next week. However we've started encountering a very weird issue where, in production, on some iOS devices, the recording will always refuse to start. Permissions, restarting, nothing else helps.

Aside from this also metering does not work in production builds.

I cannot provide more detail to this, since I don't have it either. I cannot reproduce the bug and the only thing I'm seeing in sentry is:

Error: Unknown St13runtime_error error.

which I'm assuming is a messed up version of std::runtime_error

Library version

0.2.9

Project type

Expo (bare workflow)

React Native version

0.79.6

Expo SDK version (if applicable)

SDK 53

Environment info

System:
  OS: macOS 26.0.1
  CPU: (14) arm64 Apple M4 Max
  Memory: 253.97 MB / 36.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.20.0
    path: /Users/ahmed/.nvm/versions/node/v22.20.0/bin/node
  Yarn:
    version: 1.22.22
    path: /Users/ahmed/.nvm/versions/node/v22.20.0/bin/yarn
  npm:
    version: 10.9.3
    path: /Users/ahmed/.nvm/versions/node/v22.20.0/bin/npm
  Watchman: Not Found
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.0
      - iOS 26.0
      - macOS 26.0
      - tvOS 26.0
      - visionOS 26.0
      - watchOS 26.0
  Android SDK: Not Found
IDEs:
  Android Studio: 2025.1 AI-251.26094.121.2513.14007798
  Xcode:
    version: 26.0.1/17A400
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: javac 25
    path: /usr/bin/javac
  Ruby:
    version: 3.4.7
    path: /opt/homebrew/opt/ruby/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.2
    wanted: ^20.0.2
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.6
    wanted: 0.79.6
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found


_Note: We are using hermes and the new architecture_

Steps to reproduce

I have been entirely unable to reproduce the issue. In general it is a problem that all the issues I get from this library are std::runtime_error issues.

Reproducible example repository

N/A

[ahmed-sudowrite]

Update: Not explicitly setting the path solves the issue, but in turn introduces a new one where the resulting files are corrupted. From ffmpeg, using ffprobe

[mov,mp4,m4a,3gp,3g2,mj2 @ 0xa9ec5c000] Unsupported 'chnl' box with version 1, flags: 0error reading header