Skip to content

❓ Troubleshooting and FAQ

Flutter installation

  • If you install Android and you see this output when running flutter doctor: 
    [!] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
✗ cmdline-tools component is missing
Run path/to/sdkmanager --install "cmdline-tools;latest
    Run the following steps:
    1. Open Android Studio
    2. Select More Actions > SDK Manager
    3. Under the SDK Tools tab, select Android SDK Command-line Tools (latest) (see screenshot below).
    4. Click Apply to proceed with installation.
  • When activating the FlutterFire CLI (step 1.3 in the Flutter doc: dart pub global activate flutterfire_cli), you may see a prompt to update your path: 
    Warning: Pub installs executables into $HOME/.pub-cache/bin, which is not on your path.
    You can fix that by adding this to your shell's config file (.zshrc, .bashrc, .bash_profile, etc.): 
    export PATH="$PATH":"$HOME/.pub-cache/bin"
    After adding the recommended export to your ~/.zshrc file, restart all terminal windows.

Cloud Functions Emulator

  • Functions fail to emulate: If you run firebase emulators:start --only ... and you get a message saying that function emulation failed to start, you may need to run firebase init functions on first launch. Use the following selections after running:
? What language would you like to use to write Cloud Functions? JavaScript
? Do you want to use ESLint to catch probable bugs and enforce style? Yes
? File functions/package.json already exists. Overwrite? No
i  Skipping write of functions/package.json
✔  Wrote functions/.eslintrc.js
✔  Wrote functions/index.js
? File functions/.gitignore already exists. Overwrite? No
i  Skipping write of functions/.gitignore
? Do you want to install dependencies with npm now? Yes

If you see an error message indicating ports are taken such as the one below, run sudo lsof -i tcp:<PORT_ID> to get the PID, then run kill -9 <PID> to stop the running emulator.

i  emulators: Starting emulators: auth, functions, firestore, database, pubsub
⚠  pubsub: Port 8085 is not open on 0.0.0.0, could not start Pub/Sub Emulator.
⚠  pubsub: To select a different host/port, specify that host/port in a firebase.json config file:
      {
        // ...
        "emulators": {
          "pubsub": {
            "host": "HOST",
            "port": "PORT"
          }
        }
      }
i  emulators: Shutting down emulators.

Error: Could not start Pub/Sub Emulator, port taken.
  • Integrations not working: Third-party services will not work the Functions Emulator unless you have created the file firebase/functions/.runtimeconfig.json. Please refer to the sub-section 🔑 Using Config in Emulators for further detail.