If you recently upgraded your macOS to the 10.15 Catalina release, you may get a security warnings that says "fw" cannot be opened because the developer cannot be verified. For example:
We are working on being an identified developer with Apple, but until then, follow Apple's guidelines and add the Flywheel CLI as a exception to your computer's security settings.
Open Finder, and double click on darwin_amd64.zip.
Right-click on fw, and click Open.
Click Open on the warning prompt.
A new terminal window opens, and the Flywheel CLI displays the following output:
In Terminal, navigate to ~/Downloads/darwin_amd64/.
Enter ./fw version to verify the new Flywheel CLI version.
(Optional) If you previously added fw to your PATH variable, you will need to add the updated fw version to your PATH. To do this, enter the following command:
sudo mv ./fw /usr/local/bin