Recently when I evaluate a relatively big function in slime (more that 6 lines of code) I lose connection with swank. I tried Emacs with different versions and slime with different versions, so I don't know where else I can look for an error. Could it be something with network on this particular workstation? The stack is following (for the particular function what failed to evaluate): close-connection: junk in string " (setf" ... deinstall-fd-handler ;; Event history end. ;; Backtrace: (0 ((LAMBDA (SWANK-BACKEND::DEBUGGER-LOOP-FN)) #<FUNCTION (LAMBDA #) {A11068D}>)) (1 (SWANK::SAFE-BACKTRACE)) (2 (SWANK::MAKE-SWANK-ERROR #<SWANK::SWANK-ERROR {C9492F9}>)) (3 ((FLET #:LAMBDA2855) #<SWANK::SWANK-ERROR {C9492F9}>)) (4 (SIGNAL #<SWANK::SWANK-ERROR {C9492F9}>)[:EXTERNAL]) (5 (ERROR #<SWANK::SWANK-ERROR {C9492F9}>)[:EXTERNAL]) (6 ((FLET #:LAMBDA2855) #<SB-INT:SIMPLE-PARSE-ERROR {C750239}>)) (7 (SIGNAL #<SB-INT:SIMPLE-PARSE-ERROR {C750239}>)[:EXTERNAL]) (8 (ERROR SB-INT:SIMPLE-PARSE-ERROR)[:EXTERNAL]) (9 (PARSE-INTEGER " (setf")[:EXTERNAL]) (10 (SWANK::READ-PACKET #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}>)) (11 (SWANK::DECODE-MESSAGE #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}>)) (12 (SWANK::WAIT-FOR-EVENT/EVENT-LOOP (OR (:EMACS-REX . SWANK::_) (:EMACS-CHANNEL-SEND . SWANK::_)) T)) (13 (SWANK::WAIT-FOR-EVENT (OR (:EMACS-REX . SWANK::_) (:EMACS-CHANNEL-SEND . SWANK::_)) T)) (14 (SWANK::PROCESS-REQUESTS T)) (15 (SB-IMPL::SUB-SUB-SERVE-EVENT NIL NIL)) (16 (SB-IMPL::SUB-SERVE-EVENT NIL NIL NIL)) (17 (SB-SYS:WAIT-UNTIL-FD-USABLE 10 :INPUT NIL)) (18 (SB-IMPL::REFILL-INPUT-BUFFER #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}>)) (19 (SB-IMPL::INPUT-CHAR/UTF-8 #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}> NIL :EOF)) (20 (SB-IMPL::ANSI-STREAM-READ-CHAR #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}> NIL :EOF #<unavailable argument>)) (21 (SB-IMPL::ANSI-STREAM-READ-SEQUENCE ..)) (22 (READ-SEQUENCE ..)[:EXTERNAL]) (23 (SWANK::READ-CHUNK #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}> 627)) (24 (SWANK::READ-PACKET #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}>)) (25 (SWANK::DECODE-MESSAGE #<SB-SYS:FD-STREAM for "a socket" {C5C30E1}>)) (26 (SWANK::WAIT-FOR-EVENT/EVENT-LOOP (OR (:EMACS-REX . SWANK::_) (:EMACS-CHANNEL-SEND . SWANK::_)) T)) (27 (SWANK::WAIT-FOR-EVENT (OR (:EMACS-REX . SWANK::_) (:EMACS-CHANNEL-SEND . SWANK::_)) T)) (28 (SWANK::PROCESS-REQUESTS T)) (29 ((LAMBDA ()))) (30 ((LAMBDA (SWANK-BACKEND::HOOK SWANK-BACKEND::FUN)) #<FUNCTION SWANK:SWANK-DEBUGGER-HOOK> #<CLOSURE (LAMBDA #) {C74E74D}>)) (31 (SWANK::CALL-WITH-BINDINGS ..)) (32 (SWANK::CALL-WITH-CONNECTION #<SWANK::CONNECTION {C5C3A79}> #<CLOSURE (LAMBDA #) {C74E74D}>)) (33 (SWANK::HANDLE-REQUESTS #<SWANK::CONNECTION {C5C3A79}> T)) (34 (SB-IMPL::SUB-SUB-SERVE-EVENT NIL NIL)) (35 (SB-IMPL::SUB-SERVE-EVENT NIL NIL NIL)) (36 (SB-SYS:WAIT-UNTIL-FD-USABLE 0 :INPUT NIL)) (37 (SB-IMPL::REFILL-INPUT-BUFFER #<SB-SYS:FD-STREAM for "standard input" {C10A859}>)) (38 (SB-IMPL::INPUT-CHAR/UTF-8 #<SB-SYS:FD-STREAM for "standard input" {C10A859}> NIL #:EOF-OBJECT)) (39 (READ-CHAR #<SB-SYS:FD-STREAM for "standard input" {C10A859}> NIL #:EOF-OBJECT #<unused argument>)) (40 (READ-CHAR #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {9137511}> NIL #:EOF-OBJECT #<unused argument>)) (41 (SB-IMPL::%READ-PRESERVING-WHITESPACE #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {9137511}> NIL (NIL) T)) (42 (SB-IMPL::%READ-PRESERVING-WHITESPACE #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {9137511}> NIL (NIL) NIL)) (43 (READ #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {9137511}> NIL (NIL) NIL)) (44 (SB-IMPL::REPL-READ-FORM-FUN #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDIN* {9137511}> #<unavailable argument>)) (45 (SB-IMPL::REPL-FUN NIL)) (46 ((LAMBDA ()))) (47 (SB-IMPL::%WITH-REBOUND-IO-SYNTAX #<CLOSURE (LAMBDA #) {C5AAAFD}>)) (48 (SB-IMPL::TOPLEVEL-REPL NIL)) (49 ((LABELS SB-IMPL::RESTART-LISP))) ;; Connection to Emacs lost. [ ;; condition: junk in string " (setf" ;; type: SWANK::SWANK-ERROR ;; encoding: NIL style: :FD-HANDLER dedicated: NIL] Thank you, Andrei