久々にFlutterを起動しようとしたときにアップデートをしたい場合のメモです。

Flutter アップデート方法

doctor を実行する

$ flutter doctor

実行するとアップデートの通知やIDEのバージョン互換のエラーとか教えてくれます。

  ╔════════════════════════════════════════════════════════════════════════════╗
  ║ A new version of Flutter is available!                                     ║
  ║                                                                            ║
  ║ To update to the latest version, run "flutter upgrade".                    ║
  ╚════════════════════════════════════════════════════════════════════════════╝


Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.9.1+hotfix.6, on Mac OS X 10.15.4 19E287, locale
    ja-JP)
 
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[✓] Xcode - develop for iOS and macOS (Xcode 11.4.1)
[!] Android Studio (version 3.6)
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
[✓] VS Code (version 1.44.2)
[!] Connected device
    ! No devices available

! Doctor found issues in 2 categories.

flutter upgrade　でアップデートする

$ flutter upgrade

アップデートに10分〜とかかるが、エラーが出なければ成功。

念の為バージョンの確認

$ flutter --version

Flutter 1.12.13+hotfix.9 • channel stable •
https://github.com/flutter/flutter.git
Framework • revision f139b11009 (5 weeks ago) • 2020-03-30 13:57:30 -0700
Engine • revision af51afceb8
Tools • Dart 2.7.2

以上です。