I have succeeded in building and installing the Coot-gtk3 branch manually on my Mac (macOS Big Sur 11.2.1), but the installation fails when using the Formula described above. Now I'm building coot-gtk3 Formula on, but it does't work well yet. Recently, I've made rdkit formula for this purpose, which was merged into Homebrew-core ( ). As you've already noticed, I am planning to create a Homebrew formula of the latest version of Coot, especially one with gtk+3 GUI.
