ps: There is no need to download homebrew, Xcode and upgrade mac OS.
1. First download Flutter 2.0.6
website: Flutter installation package download
2. Unzip the package and copy it to the folder where the original Flutter is located
3. Open Android Studio and manually switch the Flutter path
4. Change the environment variable
(1) If it is zsh:
root Run vim .zshrc in the directory, enter i to edit, then change the Flutter version, exit and save after the change (operate esc—>shift+:—>wq).
(2) If it is bash:
run vim .bash_profile in the root directory, and the follow-up is the same as zsh.
In this way, the upgrade is successful.