asdf uses FORMATTER quite a bit. LispWorks expands
this at compile-time. However, the generated closure
calls the internal function LW-XP::PPRINT-POP-CHECK+TOP
(to handle "~@<") but doesn't load the library that
defines it. So if asdf is compiled, then loaded into a
fresh Lisp, and then used, it will break.
This has been fixed in LispWorks 4.3, but is broken in
A suitable workaround is to use #+lispworks (require
"formatter") at runtime.