Sep 5, 2022, 6:25:45 PMSep 5
If you build Firefox for macOS, the required SDK is now at least 11.3
(up from 11.0).
If you are using macOS 10.15 or earlier, you have two options: You can
upgrade to 11.0+ and install Xcode 12.5 or newer, or you can copy the
11.3 SDK from a newer Xcode installation to your system.
If you're using macOS 11.0 or later, use Xcode version 12.5 or newer.