Install cl-clx-sbcl by entering the following commands in the terminal:
sudo apt update sudo apt install cl-clx-sbcl
X11 Common Lisp client library for SBCL
CLX is a low-level X11 client library for Common Lisp. CLX is to Lisp what Xlib is to C. . This version of CLX originated in a CMUCL distribution, was modified in order to make it compile and run under SBCL and was enhanced with some features from other CLX implementations. It currently runs only on SBCL, but it might be ported to other Common Lisp implementations.