The Firebase dSYM Upload step won’t work if the app was previously linked from Fabric to Firebase Crashlytics. The dSYM files are still missing in Fabric after successful BitRise builds. No issues are reported by the step when building.
In the new Firebase dSYM uploading instructions it says:
Important: If you’re working with an app that you previously linked from Fabric to Firebase Crashlytics, pass in your Fabric API Key to run the upload symbols script. That is, in the following options to run the script, use -a fabric-api-key instead of -gsp path/to/GoogleService-Info.plist .
If you’re using BitCode, the dsyms uploaded from your build on Bitrise are virtually worthless and you need to download the ones provided by AppStoreConnect.