As part of the continued effort to increase ABCL's practical usability (as opposed to its theoretical compliance to the CLHS), we've fixed compilation problems where ABCL would crash with a stack overflow when compiling CLOSURE-HTML.
The problem turned out to be that ABCL's fasl format didn't support serialization of circular structures. Apparently, very few libraries actually use the ability to serialize circular literals, but CLOSURE-HTML does.
The fix required changing the FASL version number. If you're working off trunk, you'll be required to do a full recompile of your work.