Let sly access the current project root asdf system

init.el

@@ -587,6 +587,21 @@
   (sly-symbol-completion-mode nil)
   :config
   (setq inferior-lisp-program "sbcl")
+  (defun my--sly-add-project-root-to-asdf (old-init)
+    (let ((dir (if-let* ((proj (project-current))
+                         (root (project-root proj)))
+                   root
+                 default-directory)))
+      (if (directory-files dir nil "\\.asd\\'" t 1)
+          (let ((old-init-list (read old-init)))
+            (setf (cddadr old-init-list)
+                  (cons `(push (pathname ,(sly-to-lisp-filename dir))
+                               (symbol-value
+                                (read-from-string "asdf:*central-registry*")))
+                        (cddadr old-init-list)))
+            (format "%S\n\n" old-init-list))
+        old-init)))
+  (advice-add #'sly-init-using-asdf :filter-return #'my--sly-add-project-root-to-asdf)
   (sly-setup)
   (with-eval-after-load 'meow
     (add-to-list 'meow-mode-state-list '(sly-db-mode . motion))))