If you don't want to make dired/helm asynchronous disable it with `dired-async-mode`.
+### Debian and Ubuntu
+
+Users of Debian 9 or later or Ubuntu 16.04 or later may simply `apt-get install elpa-async`.
+
## Enable asynchronous compilation of your (M)elpa packages
By default emacs package.el compile packages in its running emacs session.