DSYM

A dSYM is a debug symbol bundle used by Apple platforms to map crash report addresses to human-readable symbol names, lines, and source references. It accompanies an application binary and is essential for debugging crashes. The dSYM provides the DWARF debug information for each architecture and is generated during the build or archive process.

A dSYM bundle typically resembles YourApp.app.dSYM and contains Contents/Resources/DWARF/YourApp, along with metadata such as Contents/Info.plist. The DWARF data stores symbol names, addresses, and line information, organized per architecture so crash reports can be symbolicated accurately.

Generation and configuration: In Xcode, the build setting Debug Information Format is commonly set to DWARF with dSYM File. Building or archiving creates a dSYM for each architecture and stores it in the resulting .dSYM bundle. The presence of the correct dSYM is necessary for effective symbolication of crash logs.

Usage and matching: Crash reporting tools use the dSYM to translate addresses in a crash report to function names and source lines. The binary and the corresponding dSYM must share the same UUID to enable proper symbolication; otherwise, addresses remain unresolved. When distributing apps, ensure the appropriate dSYM is available to developers or automated crash-reporting services.

Bitcode considerations and retention: If Bitcode is enabled, Apple may recompile the app for distribution, and the final dSYM required for symbolication of user crashes may need to be downloaded from App Store Connect after processing. It is best practice to retain and organize dSYMs alongside archived builds, and to manage access securely to prevent exposure of internal identifiers.