So, ive decided I should probably use ecl lisp. So heres da problem. Examine this output that produced an error: (:emacs-rex ;;the request (swank:connection-info) "COMMON-LISP-USER" t 1) ;; response – read error given below!! Debugger entered: nil (condition-case error (slime-net-read) (error (debug) (slime-net-close process t) (error "net-read error: %S" error))) slime-net-read-or-lose(#<process SLIME Lisp>) slime-process-available-input(#<process SLIME Lisp>) slime-net-filter(#<process SLIME Lisp> ;;the response which produced above error 13(:return (:ok (:pid 5548 :style nil :lisp-implementation (:type \"ECL\" :name \"ECL\" :version \"9.12.3\") :machine (:instance \"SE\")) 1) ;;ß---------------Threading issue??? TH-PC\" :type \"x86\" :version \"17\") ;;ß----Should be “SETH-PC but its broken up!!!! :features (:wsock :win32 :formatter :uint32-t :uint16-t :relative-package-names :unicode :dffi :clos-streams :cmu-format :msvc :ecl-pde :dlopen :clos :threads :boehm-gc :ansi-cl :common-lisp :ieee-floating-point :prefixed-api :ffi :pentium4 :common :ecl) :modules (\"SB-BSD-SOCKETS\" \"SOCKETS\") :package (:name \"COMMON-LISP-USER\" :prompt \"CL-USER\") :version \"2009-12-23") Compare this with the pristine clisp output (:emacs-rex (swank:connection-info) "COMMON-LISP-USER" t 1) (:indentation-update (("with-c-var" . 1) ("with-c-place" . 1) ("with-foreign-string" . 1) ("with-foreign-object" . 1) ("with-defining-c-type" . 1) ("with-name/options" . 1) ("with-window" . 0) ("with-output-to-printer" . 1) ("define-setf-method" . 2) ("letf*" . 1) ("letf" . 1) ("muffle-cerrors" . 0) ("without-global-handlers" . 0) ("with-http-output" . 1) ("with-collect" . 1) ("with-http-input" . 1) ("without-package-lock" . 1) ("appease-cerrors" . 0) ("with-restarts" . 1) ("fcase" . 2) ...)) (:return (:ok (:pid 5748 :style nil :lisp-implementation (:type "CLISP" :name "clisp" :version "2.48 (2009-07-28) (built on stnt067 [192.168.0.1])") :machine (:instance "Seth-PC [192.168.2.3]" :type "PC/386" :version "PC/A86") :features (:cl-fad cffi-features:x86 cffi-features:windows :cffi :x86 :windows :little-endian :asdf :readline :regexp :syscalls :i18n :loop :compiler :clos :mop :clisp :ansi-cl :common-lisp :lisp=cl ...) :modules ("SWANK-ARGLISTS" "SWANK-C-P-C" "ASDF" "readline" "regexp" "syscalls" "i18n") :package (:name "COMMON-LISP-USER" :prompt "CL-USER") :version "2009-12-23")) 1) So… Recently ecl had made threading a requirement for windows, and maybe for some other platforms. I don’t know if this was the start of the bug as I have not yet gone back in ecl versions and seen which one works. The error on startup DOES NOT occur consistently which is very puzzling. But, anyways, I would like ecl lisp to act like a ‘single threaded lisp’ as far as slime is concerned so that I can eliminate threading issues generated by the slime lisp code.