First of all, make sure you are using a version of Flutter framework >= 1.16.2, you can check it by running:
flutter --version
And if it's not the case, you can upgrade the Flutter framework by running:
flutter upgrade
Then, in order to generate the symbol map files when you run the flutter build
command, you can use the command like this:
flutter build apk --obfuscate --split-debug-info=some_parent_directory/some_child_directory
Note that some_parent_directory and some_child_directory are arbitrary names that you can replace for whatever you want.
Also note that there's no slash (/) symbol at the beggining of the right side of the equals (=) symbol of the --split-debug-info=some_parent_directory/some_child_directory
part of the command.
For the example above, after the command finishes, you can find a some_parent_directory directory under your project's root directory, which contains another directory called some_child_directory which finally contains the symbol map files:
- app.android-arm.symbols
- app.android-arm64.symbols
- app.android-x64.symbols