Hello,

 It will be interesting to know the general policy regarding the issues with wrong arguments types during the form compilation. Should SBCL check everything it can check? For example, this issue

https://bugs.launchpad.net/sbcl/+bug/576594

exists also in CLISP and Lispworks. But this code is unlikely to be written by somebody, unless he or she do not know about DEFTYPE syntax at all. Should SBCL have a protection against such non-standard usage attempts? Or we assume users to be smart enough and therefore we should not pay our attention to such problems? I am asking about this, because there are probably many similar issues - should I report them in the future or not? I have already put some of them to Launchpad, but they mostly involve the crazy code which is unlikely to occur in real life:

https://bugs.launchpad.net/sbcl/+bug/573956
https://bugs.launchpad.net/sbcl/+bug/573968


Regards,
Roman