This option provides a more convenient way to overlay dummy packages.
It also adds a function `config.lib.test.mkStubPackage` that can,
e.g., be used for `package` options.
Foot is a fast terminal emulator for Wayland. It can optionally be run
in a client-server configuration.
There are three unit tests to handle an empty configuration, the
default configuration, and systemd service file generation.
