Comment 12 for bug 1855272

my personal experience is that CLISP miscompiles SBCL, and I think this is the experience of other SBCL developers as well.
On the other hand, there was a point in time at which I though CLISP was reliable enough to use.
(I don't know what happened - did our code get more complicated to the point that CLISP miscompiles it which then leads to it miscompiling itself? That seems to be the only explanation)

So there are (at least) two ways to go about finding the problems-
(1) byte-for-byte compare the .fasl files resulting from compiling SBCL under SBCL vs compiling SBCL under CLISP. This should narrow down discrepancies to a file or bunch of files.
(2) start from first principles of debugging - lots of stepping and backtracing and printfs
Unfortunately I don't have the time or need to do either of the above.

If nothing else, please attach a backtrace by entering 'b' at the ldb> prompt.