exn found:#(struct:exn:fail:filesystem:errno delete-directory: cannot delete directory
  path: /Users/apple/Library/Application Support/aoi
  system error: Directory not empty; errno=66 #<continuation-mark-set> (66 . posix))

(define lib-folder '("/Users/apple/Library/Application Support/aoi"))
(define (del-lib-folder)
  (for-each (λ (p)
              (printf "del lib folder:~a~n" p)
              (if (directory-exists? p)
                  (delete-directory p)
                  (printf "folder does not exist:~a~n" p)))
            lib-folder))

# rmdir dir
rmdir: failed to remove 'dir/': Directory not empty

# rm -r dir
#

(define lib-folder '("/Users/apple/Library/Application Support/aoi"))
(define (del-lib-folder)
(for-each (λ (p)
          (printf "del lib folder:~a~n" p)
          (delete-directory/files #:must-exist? #f p))
        lib-folder))