#no such module 'RxSwift'の場合Podfileに以下を追加
TARGETS -> Build Settings -> Architectures -> Excluded Architecturesに「arm64」追加
post_install do |installer|
installer.pods_project.build_configurations.each do |config|
config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64"
end
end
*実機にするときは「arm64」削除必要