I had not thought to check for any environment differences because both evaluations were done using Slime from a single Emacs buffer using C-x C-e (bound to `slime-eval-last-expression') and C-c C-p (bound to `slime-pprint-eval-last-expression'). Evaluation of *PRINT-CIRCLE* from the same buffer yields NIL. The following expression has the same problem:
it's not environmental differences, but a peculiarity of slime's implementation. one of them calls SWANK:INTERACTIVE-EVAL on the CL side, and the other calls SWANK:PPRINT-EVAL. the latter configures the printer differently (i.e. enables *PRINT-CIRCLE*). but notice that the two outputs are the same semantically. one of them just also annotates the cons cell identities. in short: it's a peculiarity of the current slime implementation, but i wouldn't call it a bug. -- • attila lendvai • PGP: 963F 5D5F 45C7 DFCD 0A39 -- “Heed these words, you who wish to probe the depths of nature: if you do not find within yourself that which you seek, neither will you find it outside. If you ignore the wonders of your own house, how do you expect to find other wonders? In you is hidden the treasure of treasures. Know Thyself and you will know the Universe and the Gods.” — Oracle of Delphi, (c. 8th century BC)