[Solved]-Flutter 2.0 giving pub get failed(server unavailable) on mac running BigSur-Flutter

I had the same problem. I tried so hard to solve it, and I finally found the solution in this page: Flutter pub.get stopped working, even on vanilla install : socket error trying to find package xxx

It is because of the antivirus (which is SOPHOS I use with my Mac). I uninstalled it and it works perfectly

You need to correctly set up your flutter path.

from here https://flutter.dev/docs/get-started/install/macos#update-your-path

Determine the directory where you placed the Flutter SDK. You will need this in Step 3. Open (or create) $HOME/.bash_profile. You can do that by using terminal text editor by going in terminal and typing nano ~/.bash_profile macOS Catalina uses the Z shell by default, so edit $HOME/.zshrc.

If you are using a different shell, the file path and filename will be different on your machine.

Add the following line and change [PATH_TO_FLUTTER_GIT_DIRECTORY] to be the path where you cloned Flutter’s git repo: export PATH=[PATH_TO_FLUTTER_GIT_DIRECTORY]/flutter/bin:$PATH

for example:

export PATH=~/Documents/flutter/bin:$PATH

press CTRL X and when it asked you to save the file, choose yes

Run source $HOME/.bash_profile to refresh the current window or restart the terminal

Verify that the flutter/bin directory is now in your PATH by running: echo $PATH

Notice that [PATH_TO_FLUTTER_GIT_DIRECTORY] is where you installed flutter SDK, not the location of your app

Instead of nano, you can use any text editor to edit ~/.bash_profile