John, why do I get this error?

 

 

Connection failure to X0.0 server  display 0:

   [Condition of type XLIB:CONNECTION-FAILURE]

 

Restarts:

 0: [RETRY] Retry SLIME interactive evaluation request.

 1: [*ABORT] Return to SLIME's top level.

 2: [ABORT-BREAK] Reset this thread

 3: [ABORT] Kill this thread

 

Backtrace:

  0: (XLIB::X-ERROR XLIB:CONNECTION-FAILURE :MAJOR-VERSION 0 :MINOR-VERSION 0 :HOST "" :DISPLAY 0 :REASON "")

  1: (XLIB::DISPLAY-CONNECT #<DISPLAY :0 ( R0)> :AUTHORIZATION-NAME "MIT-MAGIC-COOKIE-1" :AUTHORIZATION-DATA #(39 59 136 212 135 94 ...))

  2: (XLIB:OPEN-DISPLAY "" :DISPLAY 0 :PROTOCOL :LOCAL :AUTHORIZATION-NAME "MIT-MAGIC-COOKIE-1" :AUTHORIZATION-DATA #(39 59 136 212 135 94 ...))

  3: (#<STANDARD-METHOD CLIM-CLX::INITIALIZE-CLX (CLIM-CLX::CLX-BASIC-PORT)> #<CLX-PORT  #x3020054F10AD>)

  4: (#<STANDARD-METHOD INITIALIZE-INSTANCE :AFTER (CLIM-CLX::CLX-PORT)> #<CLX-PORT  #x3020054F10AD> :SERVER-PATH (:CLX :HOST "" :DISPLAY-ID 0 :SCREEN-ID ...))

  5: (CCL::%%BEFORE-AND-AFTER-COMBINED-METHOD-DCODE (NIL #<STANDARD-METHOD INITIALIZE-INSTANCE :AFTER (CLIM-CLX::CLX-PORT)> . 17529393327332))

  6: (CCL::%%STANDARD-COMBINED-METHOD-DCODE (NIL (#<STANDARD-METHOD INITIALIZE-INSTANCE :AFTER (CLIM:PORT)> #<STANDARD-METHOD INITIALIZE-INSTANCE :AFTER #>) ..) 17529393327332)

  7: (NIL #<Unknown Arguments>)

  8: (CCL::%MAKE-STD-INSTANCE #<STANDARD-CLASS CLIM-CLX::CLX-PORT> (:SERVER-PATH (:CLX :HOST "" :DISPLAY-ID 0 :SCREEN-ID ...)))

  9: (#<CCL::STANDARD-KERNEL-METHOD MAKE-INSTANCE (STANDARD-CLASS)> #<STANDARD-CLASS CLIM-CLX::CLX-PORT> :SERVER-PATH (:CLX :HOST "" :DISPLAY-ID 0 :SCREEN-ID ...))

 10: (#<CCL::STANDARD-KERNEL-METHOD MAKE-INSTANCE (SYMBOL)> CLIM-CLX::CLX-PORT :SERVER-PATH (:CLX :HOST "" :DISPLAY-ID 0 :SCREEN-ID ...))

 11: (CLIM:FIND-PORT :SERVER-PATH (:CLX :HOST "" :DISPLAY-ID 0 :SCREEN-ID ...))

 12: (CLIM:FIND-FRAME-MANAGER)

 13: (#<STANDARD-METHOD CLIM:RUN-FRAME-TOP-LEVEL :AROUND (CLIM:APPLICATION-FRAME)> #<COM.SYMSIM.OSS.QL-GUI::QUICKLISP-GUI #x3020054ECB5D>)

 14: (CCL::%%STANDARD-COMBINED-METHOD-DCODE (#<STANDARD-METHOD CLIM:RUN-FRAME-TOP-LEVEL :AROUND (CLIM:APPLICATION-FRAME)> #<STANDARD-METHOD CLIM:RUN-FRAME-TOP-LEVEL (CLIM:APPLICATION-FRAME)>) 1752939332740..

 15: (NIL #<Unknown Arguments>)

 16: (CCL::CALL-CHECK-REGS COM.SYMSIM.OSS.QL-GUI:RUN)

 17: (CCL::CHEAP-EVAL (COM.SYMSIM.OSS.QL-GUI:RUN))

 18: ((:INTERNAL SWANK:INTERACTIVE-EVAL))

 19: (SWANK::CALL-WITH-RETRY-RESTART "Retry SLIME interactive evaluation request." #<COMPILED-LEXICAL-CLOSURE (:INTERNAL SWANK:INTERACTIVE-EVAL) #x3020054ECD7F>)

 20: (SWANK::CALL-WITH-BUFFER-SYNTAX NIL #<COMPILED-LEXICAL-CLOSURE (:INTERNAL SWANK:INTERACTIVE-EVAL) #x3020054ECDBF>)

 21: (CCL::CALL-CHECK-REGS SWANK:INTERACTIVE-EVAL "(com.symsim.oss.ql-gui:run)")

 22: (CCL::CHEAP-EVAL (SWANK:INTERACTIVE-EVAL "(com.symsim.oss.ql-gui:run)"))

 23: (SWANK:EVAL-FOR-EMACS (SWANK:INTERACTIVE-EVAL "(com.symsim.oss.ql-gui:run)") "COMMON-LISP-USER" 20)

 24: ((:INTERNAL SWANK::SPAWN-WORKER-THREAD))

 25: (SWANK/BACKEND:CALL-WITH-DEBUGGER-HOOK #<Compiled-function SWANK:SWANK-DEBUGGER-HOOK #x302001C92B5F> #<Compiled-function (:INTERNAL SWANK::SPAWN-WORKER-THREAD) (Non-Global)  #x302001C5A87F>)

 26: (SWANK::CALL-WITH-BINDINGS ((*STANDARD-INPUT* . #<SWANK/GRAY::SLIME-INPUT-STREAM #x3020008EE61D>) (*STANDARD-OUTPUT* . #<SWANK/GRAY::SLIME-OUTPUT-STREAM #x3020008EE53D>) ..))) #<COMPILED-LEXICAL-CLOSU..

 27: ((:INTERNAL SWANK::SPAWN-WORKER-THREAD))

 28: (CCL::RUN-PROCESS-INITIAL-FORM #<PROCESS worker(40) [Active] #x3020054E2FCD> (#<COMPILED-LEXICAL-CLOSURE (:INTERNAL CCL::%PROCESS-RUN-FUNCTION) #x3020054E2D5F>))

 29: ((:INTERNAL (CCL::%PROCESS-PRESET-INTERNAL (PROCESS))) #<PROCESS worker(40) [Active] #x3020054E2FCD> (#<COMPILED-LEXICAL-CLOSURE (:INTERNAL CCL::%PROCESS-RUN-FUNCTION) #x3020054E2D5F>))

 30: ((:INTERNAL CCL::THREAD-MAKE-STARTUP-FUNCTION))