require "requirement" class TuntapRequirement < Requirement fatal true cask "tuntap" satisfy(build_env: false) { self.class.binary_tuntap_installed? } def self.binary_tuntap_installed? %w[ /Library/Extensions/tun.kext /Library/Extensions/tap.kext /Library/LaunchDaemons/net.sf.tuntaposx.tun.plist /Library/LaunchDaemons/net.sf.tuntaposx.tap.plist ].all? { |file| File.exist?(file) } end end