MRuby::Toolchain.new(:clang) do |conf, _params| toolchain :gcc [conf.cc, conf.objc, conf.asm].each do |cc| cc.command = ENV['CC'] || 'clang' end conf.cxx.command = ENV['CXX'] || 'clang++' conf.linker.command = ENV['LD'] || 'clang' end