Install sawfish-lisp-source by entering the following commands in the terminal:
sudo apt update sudo apt install sawfish-lisp-source
Description:
sawfish lisp files
This package contains the lisp source files in case you want to modify, study or debug the behaviour of the window manager. . It is not required for normal use of sawfish and not installing it will save space in small systems.
Homepage: http://sawfish.tuxfamily.org/
Version: 1:1.11.90-1.1
Section: universe/x11