As the application author you can set the release mode in the build script so that the release flag looks like `zig build --release` instead, and the user doesn't choose the optimization mode.

As a user you can pass `--release` to `zig build` to request release mode. If the application doesn't want to pick for you, you'll get an error and then you can pick for yourself.

In this case, it looks like the author of Phoenix wants to choose ReleaseSafe as the official release mode of the application.

Phoenix is the name of my hometown, btw.