I guess I have to assume nobody is using Cells with CCL. I'm attempting to get it to work, but am a little out of my depth. To begin with, I had to add a couple of conditionals for ccl to get past initial errors. Then: ,load-system cells There is no package named "EXCL" . [Condition of type CCL::NO-SUCH-PACKAGE] I don't know what EXCL is, but I'm offered a restart to treat it as a nickname for "COMMON-LISP-USER", so I choose that: Reader error on #<BASIC-FILE-CHARACTER-INPUT-STREAM ("/Users/neil/.asdf-install-dir/site/cells/utils-kt/..."/7 ISO-8859-1) #x8D1F7CE>, near position 921, within " (mop::class-prot": Reference to unknown package "MOP". [Condition of type CCL::SIMPLE-READER-ERROR] <The above error is referring to line 36 of detritus.lisp> Any advice about how to proceed would be welcomed. I think I ought to begin by resolving the EXCL issue, but haven't had much luck finding such a package. Thanks, Neil Baylis []