I was having a case where some package wrangling in one of our systems behaved differently with new ASDF than with the ASDF 2 that ships with ACL. It seemed like there was an :AFTER method on one of my modules that simply wasn't being called. I took my usual resort and did (TRACE ASDF:PERFORM). I was very surprised to see that my (asdf:load-system "circa-csm" :force t) resulted in only four calls to perform, and all of them had to do with ASDF: CL-USER> (asdf:load-system "circa-csm" :force t) ; Loading /Users/rpg/lisp/asdf/asdf.asd ; Loading /Users/rpg/lisp/asdf/asdf-driver.asd 0[7]: (ASDF/ACTION:PERFORM #<ASDF/LISP-ACTION:PREPARE-OP > #<ASDF/SYSTEM:SYSTEM "asdf">) 0* (MULTIPLE-VALUE-PROG1 (PROGN #<STANDARD-METHOD ASDF/ACTION:PERFORM :BEFORE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)> #<STANDARD-METHOD ASDF/ACTION:PERFORM (ASDF/LISP-ACTION:PREPARE-OP ASDF/COMPONENT:COMPONENT)>) #<STANDARD-METHOD ASDF/ACTION:PERFORM :AFTER (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)>) 0[7]: returned NIL 0[7]: (ASDF/ACTION:PERFORM #<ASDF/LISP-ACTION:PREPARE-OP > #<ASDF/COMPONENT:MODULE "asdf" "build">) 0* (MULTIPLE-VALUE-PROG1 (PROGN #<STANDARD-METHOD ASDF/ACTION:PERFORM :BEFORE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)> #<STANDARD-METHOD ASDF/ACTION:PERFORM (ASDF/LISP-ACTION:PREPARE-OP ASDF/COMPONENT:COMPONENT)>) #<STANDARD-METHOD ASDF/ACTION:PERFORM :AFTER (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)>) 0[7]: returned NIL 0[7]: (ASDF/ACTION:PERFORM #<ASDF/LISP-ACTION:PREPARE-OP > #<ASDF/LISP-ACTION:CL-SOURCE-FILE "asdf" "build" "asdf">) 0* (MULTIPLE-VALUE-PROG1 (PROGN #<STANDARD-METHOD ASDF/ACTION:PERFORM :BEFORE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)> #<STANDARD-METHOD ASDF/ACTION:PERFORM (ASDF/LISP-ACTION:PREPARE-OP ASDF/COMPONENT:COMPONENT)>) #<STANDARD-METHOD ASDF/ACTION:PERFORM :AFTER (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)>) 0[7]: returned NIL 0[7]: (ASDF/ACTION:PERFORM #<ASDF/LISP-ACTION:LOAD-OP > #<ASDF/LISP-ACTION:CL-SOURCE-FILE "asdf" "build" "asdf">) 0* (MULTIPLE-VALUE-PROG1 (PROGN #<STANDARD-METHOD ASDF/ACTION:PERFORM :BEFORE (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)> #<STANDARD-METHOD ASDF/ACTION:PERFORM (ASDF/LISP-ACTION:LOAD-OP ASDF/LISP-ACTION:CL-SOURCE-FILE)>) #<STANDARD-METHOD ASDF/ACTION:PERFORM :AFTER (ASDF/OPERATION:OPERATION ASDF/COMPONENT:COMPONENT)>) ; Fast loading ; /Users/rpg/.cache/common-lisp/acl-8.2-macosx-x64/Users/rpg/lisp/asdf/build/asdf.fasl 0[7]: returned T ;;; from here on down there's lots of loading, but no recompilation (as I ;;; expected from :force t) and no calls to PERFORM. ; Fast loading ; /Users/rpg/.cache/common-lisp/acl-8.2-macosx-x64/Users/rpg/circa/code/csm/musliner-tools.fasl ; Fast loading ; /Users/rpg/.cache/common-lisp/acl-8.2-macosx-x64/Users/rpg/circa/code/csm/stochastic.fasl Or -- oh, wait! Did the recompilation of ASDF killed the tracing? If so, I don't think that :force t should be causing ASDF itself to rebuild. I understand why it's a dependency, but this shows why it's inappropriate: rebuilding asdf destroys our ability to inspect its behavior. Oh, and maybe it's also killing the PERFORM :after method in my system definition? I'd suggest :force t should stop before it gets to ASDF itself. Maybe we need to add :force :omg to do that! ;-) Cheers, r