Flutter is a UI toolkit developed by Google that allows developers to create applications for both iOS and Android from a single codebase. Because of these advantages, many developers choose Flutter and can easily create applications that run on various platforms. In this tutorial, we will explore how to use the flutter doctor command to check the Flutter development environment in detail.
1. What is ‘flutter doctor’?
flutter doctor is the first command that should be run after installing the Flutter framework. The main purpose of this command is to verify that the components required for the Flutter development environment are installed correctly and to provide information to prevent issues in advance.
2. How ‘flutter doctor’ works
Flutter requires various SDKs and tools to operate on different platforms. The flutter doctor command checks whether these tools are installed and notifies the user if additional installations are required. This command performs checks for various platforms (e.g., iOS, Android, etc.).
3. Running ‘flutter doctor’
Open the terminal and enter the following command:
flutter doctorWhen you execute the command, the terminal window will display output like the following:
[✓] Flutter (Channel stable, 3.3.5, on macOS 12.5 21G651, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 13.4.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2021.1)
[✓] VS Code (version 1.68.0)
[✓] Connected device (2 available)
[✓] Network resources
4. Interpreting the output
In the output above, the symbol in front of each item indicates the installation status:
- [✓]: Item installed correctly
- [!] : Item has a warning (e.g., some tools may not work properly)
- [✗]: Item needs installation or has issues
4.1 Flutter
The Flutter item checks if the Flutter SDK is installed correctly. If installed properly, a [✓] symbol is displayed along with version information and the OS in use.
4.2 Android toolchain
This item checks if the SDK required for Android development is installed correctly. If installed properly, a [✓] symbol is displayed along with the Android SDK version information.
4.3 Xcode
The Xcode item checks if the tools for developing on the iOS platform are installed correctly. A [✓] indicates the available version of Xcode.
4.4 Connected devices
The connected devices item checks whether a physical device for development is connected. If this item shows [✓], the device is connected properly.
4.5 Network resources
The network resources item checks whether access to resources related to Flutter is available. This item should be [✓] to ensure a smooth development environment.
5. Resolving warnings and error messages
Sometimes, when you run flutter doctor, warnings or error messages may appear. In this case, you need to understand each warning and error and find appropriate solutions.
5.1 Xcode related errors
If there are Xcode related errors, you should check if Xcode is updated to the latest version. Additionally, ensure that Xcode’s Command Line Tools are activated.
5.2 Android SDK related errors
If there are errors related to the Android SDK, you should verify whether the SDK is installed and if environment variables are set correctly. You can use Android Studio to open the SDK Manager and check if all necessary SDKs are installed.
5.3 Unconnected devices
If a warning appears in the connected devices item, you should check if the device is set to USB debugging mode and if it is connected correctly to the PC.
6. Automating environment checks with ‘flutter doctor’
To continue developing in Flutter projects over the long term, it is advisable to periodically run flutter doctor to check the development environment. This can also be used in CI/CD environments to verify that the development environment is set up correctly in each build process.
7. Conclusion
In this tutorial, we thoroughly explored the flutter doctor command. When setting up the Flutter development environment, this command can help detect initial setup errors in advance and lay the groundwork for smooth and efficient development.
In the future, we will cover various topics related to Flutter, and we plan to write articles that assist developers’ understanding. If you want to learn more about Flutter development, please look forward to the next tutorial!