Update installation instructions.

Author: svetlyak40wt

README.md

@@ -106,17 +106,23 @@ If you want to autoload the patch, do two things:
 2. Add this code to your `~/.sbclrc` or `~/.roswell/init.lisp`:
 
    ```
-   (let ((fix-filename (make-pathname :directory '(:absolute :home ".quicklisp-client-fix")
-                                      :name "quicklisp-fix"
-                                      :type "lisp")))
-     (let ((quicklisp-found #+quicklisp t
-                            #-quicklisp nil))
-       (cond
-         ((not quicklisp-found)
-          (warn "Quicklisp is not available, skipping fix loading.~%"))
-         ((probe-file fix-filename)
-          (handler-bind ((warning #'muffle-warning))
-            (load fix-filename)))
-         (t
-          (warn "Quicklisp fix was not found at ~S.~%" fix-filename)))))
-```
+   (handler-bind ((serious-condition
+                    (lambda (condition)
+                      (uiop:print-condition-backtrace condition)
+                      (uiop:quit 1))))
+     (let ((fix-filename (merge-pathnames
+                          (make-pathname :directory '(:relative ".quicklisp-client-fix")
+                                         :name "quicklisp-fix"
+                                         :type "lisp")
+                          (user-homedir-pathname))))
+       (let ((quicklisp-found #+quicklisp t
+                              #-quicklisp nil))
+         (cond
+           ((not quicklisp-found)
+            (warn "Quicklisp is not available, skipping fix loading.~%"))
+           ((probe-file fix-filename)
+            (handler-bind ((warning #'muffle-warning))
+              (load fix-filename)))
+           (t
+            (warn "Quicklisp fix was not found at ~S.~%" fix-filename))))))
+   ```