Thanks for your comments, Robert. I've revised the INFO-INDEX class and made it a lot simpler (and still working the same). For what it's worth, I've pasted it below.
I noticed that UIOP:COPY-FILE doesn't seem to behave well if told to copy a file to itself -- it clobbers the file. That seems like unfriendly behavior; it seems better that either it should complain or do nothing. Thanks for your help, I think I'm in good shape on this front now. best, Robert Dodier PS. ;; info-index.lisp -- ASDF component type for Maxima documentation index ;; copyright 2018 by Robert Dodier ;; I release this work under terms of the GNU General Public License (require 'asdf) (require 'uiop) (in-package :asdf) (defclass info-index (cl-source-file) ()) ;; An info index file is a Lisp source file, which is compiled ;; just the same as an ordinary Lisp file, with the additional ;; step of copying the .info to the same location to where the ;; compiler output will go. (defmethod perform ((o compile-op) (c info-index)) (let* ((system-name (component-name (component-system c))) (info-name (make-pathname :name system-name :type "info")) (info-in-file (merge-pathnames info-name (first (input-files o c)))) (info-out-file (merge-pathnames info-name (first (output-files o c))))) ;; INFO-IN-FILE and INFO-OUT-FILE should be different, ;; but just to be safe, silently refuse to copy file to itself. (unless (uiop:pathname-equal info-in-file info-out-file) (uiop:copy-file info-in-file info-out-file)) (call-next-method)))