- mas, iproute2mac, terminal-notifier have no Linux support; brew bundle skips casks and mas entries on Linux automatically but not mac-only formulae, so guard them with 'if OS.mac?' - setup.yml now sets org.gnome.desktop.input-sources sources to [('xkb', 'us')] when empty; GNOME ignores xkb-options (caps lock mapping) while it has no managed layout