10:28:06luisah, I think I've reproduced it. It gets confused with the exception handling frames indeed. What parameters are you passing to sb-debug:print-backtrace to get that backtrace?
10:28:37ShinmeraThe trace is produced by dissect https://github.com/shinmera/dissect
11:41:44luisShinmera: SB-KERNEL:INTERNAL-ERROR binds SB-DEBUG:*STACK-TOP-HINT* to the frame that caused the error. That frame is below the foreign functions that handle the exception, so the backtrace doesn't get confused.
11:49:14ShinmeraEasy enough patch to Dissect I suppose.
11:51:56luiswatch out that it's not always a frame, sometimes it's just a symbol and you need to apply SB-DEBUG::RESOLVE-STACK-TOP-HINT on it. See SWANK's CALL-WITH-DEBUGGING-ENVIRONMENT.