Cant create wigets to store it in variable

[Filipp-Druan]

I tried to compile this code:

(ql:quickload '(cl-gtk4))

(defpackage gui.example
  (:use :cl :gtk4))

(in-package gui.example)

(defvar *setting-box*
  (let ((box          (make-box :orientation +orientation-vertical+
                                :spacing 2))
        (hello-button (make-button :label "Hello!"))
        (reset-button (make-button :label "Reset")))

    (declare (ignore hello-button reset-button box))
    (print "Hello!")))

And I got this error:

Unhandled memory fault at #x0.
   [Condition of type SB-SYS:MEMORY-FAULT-ERROR]

Restarts:
 0: [ABORT] Abort compilation.
 1: [*ABORT] Return to SLY's top level.
 2: [ABORT] abort thread (#<THREAD tid=32076 "slynk-worker" RUNNING {1003D4E6A3}>)

Backtrace:
 0: (SB-SYS:MEMORY-FAULT-ERROR #<unused argument> #.(SB-SYS:INT-SAP #X00000000))
 1: ("foreign function: call_into_lisp_")
 2: ("foreign function: handle_memory_fault_emulation_trap")
 3: ("foreign function: #x555680C99CD7")
 4: ((LAMBDA (&REST GIR::ARGS-IN) :IN GIR::BUILD-FUNCTION) 1 2)
 5: ((SB-C::TOP-LEVEL-FORM (SB-IMPL::%DEFVAR #1=(QUOTE *SETTING-BOX*) (SB-C:SOURCE-LOCATION) (UNLESS (SB-INT:%BOUNDP #1#) (LET (#2=# #2# . #3=(#2#)) (DECLARE . #3#) (PRINT "Hello!")))))) [toplevel]
 6: (SB-FASL::LOAD-FASL-GROUP #S(SB-FASL::FASL-INPUT :STREAM #<SB-SYS:FD-STREAM for "file /tmp/slimeiKWK87.fasl" {1003FE78D3}> :TABLE #(63 #1="/home/iam/quicklisp/local-projects/share-files/gui.lisp" :EMA..
 7: ((LAMBDA NIL :IN SB-FASL::LOAD-AS-FASL))
 8: (SB-IMPL::CALL-WITH-LOADER-PACKAGE-NAMES #<FUNCTION (LAMBDA NIL :IN SB-FASL::LOAD-AS-FASL) {1003FF23CB}>)
 9: (SB-FASL::LOAD-AS-FASL #<SB-SYS:FD-STREAM for "file /tmp/slimeiKWK87.fasl" {1003FE78D3}> NIL NIL)
10: ((LABELS SB-FASL::LOAD-STREAM-1 :IN LOAD) #<SB-SYS:FD-STREAM for "file /tmp/slimeiKWK87.fasl" {1003FE78D3}> T)
11: (SB-FASL::CALL-WITH-LOAD-BINDINGS #<FUNCTION (LABELS SB-FASL::LOAD-STREAM-1 :IN LOAD) {7FF0AD99DD6B}> #<SB-SYS:FD-STREAM for "file /tmp/slimeiKWK87.fasl" {1003FE78D3}> T #<SB-SYS:FD-STREAM for "file /..
12: (LOAD #P"/tmp/slimeiKWK87.fasl" :VERBOSE NIL :PRINT NIL :IF-DOES-NOT-EXIST :ERROR :EXTERNAL-FORMAT :DEFAULT)
13: ((FLET SLYNK-BACKEND:CALL-WITH-COMPILATION-HOOKS :IN "/home/iam/.emacs.d/elpa/sly-20230924.811/slynk/backend/sbcl.lisp") #<FUNCTION (LAMBDA NIL :IN SLYNK-BACKEND:SLYNK-COMPILE-STRING) {1003FE77BB}>)
14: ((FLET SLYNK-BACKEND:SLYNK-COMPILE-STRING :IN "/home/iam/.emacs.d/elpa/sly-20230924.811/slynk/backend/sbcl.lisp") "(defvar *setting-box* ..)
15: ((LAMBDA NIL :IN SLYNK:COMPILE-STRING-FOR-EMACS))
16: ((LAMBDA NIL :IN SLYNK::COLLECT-NOTES))
 --more--

[bohonghuang]

You must create the widget within the GTK event loop and assign it to this global variable, as most of GTK's functionality relies on the application context.