Comment 4 for bug 775712

The idea with the declarations is smart, so let us suppose that there are no technical difficulties in generating such warnings (however, I estimate the implementation to be quite complex). But should we really warn? Implementation-dependent stuff is defined in CLHS like this:

"implementation-dependent adj. describing a behavior or aspect of Common Lisp which has been deliberately left unspecified, that might be defined in some conforming implementations but not in others, and whose details may differ between implementations. A conforming implementation is encouraged (but not required) to document its treatment of each item in this specification which is marked implementation-dependent, although in some cases such documentation might simply identify the item as ``undefined.''

So, CLHS asks us to document this, not to warn about this. I still think that the best way is to update the manual, or tweak DOLIST to handle the binding in another way. However, we may ask developers on sbcl-devel to give their opinions, and in case people support this, some patch is likely to come. Feel free to write such a mail.

Anyway, thank you for reporting this and other issues, it really helps us to make SBCL better!

Best Regards,
Roman