Learning how to use the SBCL+sly debugger

common-lisp-backtrace

 0: ("undefined function" #<STANDARD-CLASS COMMON-LISP-USER::INST-ADD>)
 1: ((:METHOD DEEPEQ (T T)) #<INST-ADD {1001E94723}> #<INST-ADD {1001E947A3}>) [fast-method]
 2: (SB-INT:SIMPLE-EVAL-IN-LEXENV (DEEPEQ (MK-INST-ADD :X :Y 1) (MK-INST-ADD :X :Y 1)) #<NULL-LEXENV>)
 3: (SB-INT:SIMPLE-EVAL-IN-LEXENV (ASSERT-EQUAL (DEEPEQ (MK-INST-ADD :X :Y 1) (MK-INST-ADD :X :Y 1)) T) #<NULL-LEXENV>)
 4: (EVAL (ASSERT-EQUAL (DEEPEQ (MK-INST-ADD :X :Y 1) (MK-INST-ADD :X :Y 1)) T))
 5: (SLYNK::EVAL-REGION ";;;; -*- Mode: Common-Lisp; Author: Siddharth Bhat -*- ..)
 6: ((LAMBDA NIL :IN SLYNK:INTERACTIVE-EVAL-REGION))
 7: (SLYNK::CALL-WITH-RETRY-RESTART "Retry SLY interactive evaluation request." #<FUNCTION (LAMBDA NIL :IN SLYNK:INTERACTIVE-EVAL-REGION) {10015A3F$ 8: (SLYNK::CALL-WITH-BUFFER-SYNTAX NIL NIL #<FUNCTION (LAMBDA NIL :IN SLYNK:INTERACTIVE-EVAL-REGION) {10015A3F4B}>)
 9: (SB-INT:SIMPLE-EVAL-IN-LEXENV (SLYNK:INTERACTIVE-EVAL-REGION ";;;; -*- Mode: Common-Lisp; Author: Siddharth Bhat -*- ..)
10: (EVAL (SLYNK:INTERACTIVE-EVAL-REGION ";;;; -*- Mode: Common-Lisp; Author: Siddharth Bhat -*- ..)
11: (SLYNK:EVAL-FOR-EMACS (SLYNK:INTERACTIVE-EVAL-REGION ";;;; -*- Mode: Common-Lisp; Author: Siddharth Bhat -*- ..)
12: ((LAMBDA NIL :IN SLYNK::SPAWN-WORKER-THREAD))
13: (SLYNK-SBCL::CALL-WITH-BREAK-HOOK #<FUNCTION SLYNK:SLYNK-DEBUGGER-HOOK> #<FUNCTION (LAMBDA NIL :IN SLYNK::SPAWN-WORKER-THREAD) {10015A3C4B}>)
14: ((FLET SLYNK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/nix/store/w09rg6jnz9kgz2y65xsj5v8lqxcvgddj-emacs-sly-20211121.1002/share/emacs/site-lisp/elp$15: ((LAMBDA NIL :IN SLYNK::SPAWN-WORKER-THREAD))
16: ((FLET SB-UNIX::BODY :IN SB-THREAD::RUN))
17: ((FLET "WITHOUT-INTERRUPTS-BODY-10" :IN SB-THREAD::RUN))
18: ((FLET SB-UNIX::BODY :IN SB-THREAD::RUN))
19: ((FLET "WITHOUT-INTERRUPTS-BODY-3" :IN SB-THREAD::RUN))
20: (SB-THREAD::RUN)
21: ("foreign function: call_into_lisp")
22: ("foreign function: funcall1")