When I evaluate something in REPL which produces a lot of rapid output, sometimes I get a message "destructure-case failed: (:WRITE-STRING ... part of the output ...)" in the message area, and the corresponding output is never added to the REPL buffer. This is happens especially often when I use (trace "ENTIRE-PACKAGE") in order to debug something. I can fix the problem by editing slime.el and adding a duplicate case in the slime-dispatch-event function for :WRITE-STRING (in upper case) being the same as :write-string, but thats just fixing the symptom and the underlaying buy in Slime remains. Here is a test case that I can reproduce 100% Emacs: 22.0.51.7-multi-tty (also happened on 21.3) Slime: latest CVS Lisp: SBCL 0.9.13 x86-64 OS: SuSe 10 64bit, 2.6.15-rc6-2-smp kernel Hardware: Dual core Opteron CL-USER> (require 'cl-ppcre) NIL CL-USER> (trace "CL-PPCRE") ... bunch of output listing all functions in CL-PPCRE ... Now just do the following several times: CL-USER> (cl-ppcre::parse-string "a*b+") ... TRACE output here ... You should see the destructure-case failed messages. Note that sometimes its every other invocation, sometimes you have to do it 10 times to get it. Below is a paste from my *Messages* buffer ---------------------- *Messages* ---------------------- error in process filter: destructure-case failed: (:WRITE-STRING " 4: (CL-PPCRE::GREEDY-QUANT #S(CL-PPCRE::LEXER :STR \"a*b+\" :LEN 4 :REG 0 :POS 0 :LAST-POS NIL)) ") error in process filter: slime-dispatch-event: destructure-case failed: (:WRITE-STRING " 6: CL-PPCRE::NEXT-CHAR returned #\\+ ") error in process filter: destructure-case failed: (:WRITE-STRING " 6: CL-PPCRE::NEXT-CHAR returned #\\+ ") error in process filter: destructure-case failed: (:WRITE-STRING " 6: CL-PPCRE::NEXT-CHAR returned #\\+ ") --------------------------------------------------------- Regards, Max