Ditch READ-SYMLINK and friends. TRUENAME will do fine.

src/coleslaw.lisp

         (with-current-directory coleslaw-conf:*basedir*
           (run-program "mv" (mapcar #'namestring (list staging new-build)))
           (when (probe-file prev)
-            (cl-fad:delete-directory-and-files (read-symlink prev)))
+            (cl-fad:delete-directory-and-files (truename prev)))
           (when (probe-file curr)
-            (update-symlink prev (read-symlink curr)))
+            (update-symlink prev (truename curr)))
           (update-symlink curr new-build))))))
 
 (defun main ()

src/packages.lisp

   (:use :cl :closure-template)
   (:import-from :iolib.os #:with-current-directory
                           #:run-program)
-  (:import-from :iolib.pathnames #:file-path-namestring)
   (:import-from :alexandria #:hash-table-values
                             #:make-keyword)
   (:export #:main

src/util.lisp

 If ARGS is provided, use (apply 'format nil PATH ARGS) as the value of PATH."
   (merge-pathnames (apply 'format nil path args) coleslaw-conf:*basedir*))
 
-(defun to-pathname (file &optional (parent coleslaw-conf:*basedir*))
-  "Convert an iolib file-path back to a pathname."
-  (merge-pathnames (file-path-namestring file) parent))
-
-(defun read-symlink (path)
-  "A trivial wrapper over iolib.os that returns the pathname in the symlink PATH."
-  (to-pathname (iolib.os:read-symlink path)))
-
 (defmacro do-files ((var path &optional extension) &body body)
   "For each file on PATH, run BODY. If EXTENSION is provided, only run BODY
 on files that match the given extension."