Waybar: Crash on multiple monitors wake up

When waking up monitors from DPMS, waybar sometimes crash around this line: https://github.com/Alexays/Waybar/blob/f233d27b782c04ef128e3d71ec32a0b2ce02df39/src/bar.cpp#L33

        Signal: 11 (SEGV)
     Timestamp: Fri 2021-02-05 17:37:53 UTC (13min ago)
  Command Line: /nix/store/8nyxlm520y29bqinfb28qn0xsd5bdjgq-waybar-0.9.5/bin/waybar --config /nix/store/hi6l2j1fb5ls1q84vcgzrax6v9w4c7g5-waybar_conf.json --style /nix/store/68p5zz5prq4825yjb1ijy526avycqf25-waybar_style.css
    Executable: /nix/store/8nyxlm520y29bqinfb28qn0xsd5bdjgq-waybar-0.9.5/bin/.waybar-wrapped

I only have a partial coredump:

(gdb) bt
#0  0x000000000044067b in waybar::GLSSurfaceImpl::GLSSurfaceImpl(Gtk::Window&, waybar::waybar_output&) ()
Backtrace stopped: Cannot access memory at address 0x7ffcf02dda08

I’ll try to capture a better coredump

(gdb) disas 0x000000000044067b
Dump of assembler code for function _ZN6waybar14GLSSurfaceImplC2ERN3Gtk6WindowERNS_13waybar_outputE:
   0x00000000004405d0 <+0>:	push   %r15
   0x00000000004405d2 <+2>:	push   %r14
   0x00000000004405d4 <+4>:	push   %r13
   0x00000000004405d6 <+6>:	lea    0x8(%rdi),%r13
   0x00000000004405da <+10>:	push   %r12
   0x00000000004405dc <+12>:	mov    %rdx,%r12
   0x00000000004405df <+15>:	push   %rbp
   0x00000000004405e0 <+16>:	mov    %rsi,%rbp
   0x00000000004405e3 <+19>:	push   %rbx
   0x00000000004405e4 <+20>:	mov    %rdi,%rbx
   0x00000000004405e7 <+23>:	lea    0x18(%rbx),%r14
   0x00000000004405eb <+27>:	sub    $0x48,%rsp
   0x00000000004405ef <+31>:	mov    %fs:0x28,%rax
   0x00000000004405f8 <+40>:	mov    %rax,0x38(%rsp)
   0x00000000004405fd <+45>:	mov    $0x4b8f88,%rax
   0x0000000000440604 <+52>:	add    $0x10,%rax
   0x0000000000440608 <+56>:	mov    %rax,(%rdi)
   0x000000000044060b <+59>:	mov    %r13,%rdi
   0x000000000044060e <+62>:	call   0x4162c0 <_ZN4sigc9trackableC2Ev@plt>
   0x0000000000440613 <+67>:	mov    $0x4b8fd8,%rax
   0x000000000044061a <+74>:	mov    %rbp,0x10(%rbx)
   0x000000000044061e <+78>:	mov    %r14,%rdi
   0x0000000000440621 <+81>:	movq   $0x0,0x20(%rbx)
   0x0000000000440629 <+89>:	lea    0x8(%r12),%rsi
   0x000000000044062e <+94>:	add    $0x10,%rax
   0x0000000000440632 <+98>:	movb   $0x0,0x28(%rbx)
   0x0000000000440636 <+102>:	mov    %rax,(%rbx)
   0x0000000000440639 <+105>:	lea    0x28(%rbx),%rax
   0x000000000044063d <+109>:	mov    %rax,0x18(%rbx)
   0x0000000000440641 <+113>:	movb   $0x0,0x40(%rbx)
   0x0000000000440645 <+117>:	call   0x4177f0 <_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE9_M_assignERKS4_@plt>
   0x000000000044064a <+122>:	mov    0x10(%rbx),%rax
   0x000000000044064e <+126>:	mov    (%rax),%rdx
   0x0000000000440651 <+129>:	mov    -0x18(%rdx),%rdx
   0x0000000000440655 <+133>:	mov    0x8(%rax,%rdx,1),%rdi
   0x000000000044065a <+138>:	call   0x4177e0 <gtk_layer_init_for_window@plt>
   0x000000000044065f <+143>:	mov    0x0(%rbp),%rax
   0x0000000000440663 <+147>:	xor    %esi,%esi
   0x0000000000440665 <+149>:	mov    -0x18(%rax),%rax
   0x0000000000440669 <+153>:	mov    0x8(%rbp,%rax,1),%rdi
   0x000000000044066e <+158>:	call   0x417db0 <gtk_layer_set_keyboard_interactivity@plt>
   0x0000000000440673 <+163>:	mov    (%r12),%rdx
   0x0000000000440677 <+167>:	mov    0x10(%rbx),%rax
   0x000000000044067b <+171>:	mov    (%rdx),%rcx
   0x000000000044067e <+174>:	mov    -0x18(%rcx),%rcx
   0x0000000000440682 <+178>:	mov    0x8(%rdx,%rcx,1),%rsi
   0x0000000000440687 <+183>:	mov    (%rax),%rdx
   0x000000000044068a <+186>:	mov    -0x18(%rdx),%rdx
   0x000000000044068e <+190>:	mov    0x8(%rax,%rdx,1),%rdi
   0x0000000000440693 <+195>:	call   0x417d00 <gtk_layer_set_monitor@plt>
   0x0000000000440698 <+200>:	mov    0x10(%rbx),%rax
   0x000000000044069c <+204>:	lea    0x5718f(%rip),%rsi        # 0x497832
   0x00000000004406a3 <+211>:	mov    (%rax),%rdx
   0x00000000004406a6 <+214>:	mov    -0x18(%rdx),%rdx
   0x00000000004406aa <+218>:	mov    0x8(%rax,%rdx,1),%rdi
   0x00000000004406af <+223>:	call   0x416bc0 <gtk_layer_set_namespace@plt>
   0x00000000004406b4 <+228>:	lea    0x10(%rsp),%r12
   0x00000000004406b9 <+233>:	mov    %rbp,%rsi
   0x00000000004406bc <+236>:	mov    %r12,%rdi
   0x00000000004406bf <+239>:	call   0x416650 <_ZN3Gtk6Widget22signal_configure_eventEv@plt>
   0x00000000004406c4 <+244>:	mov    $0x58,%edi
   0x00000000004406c9 <+249>:	call   0x417a90 <_Znwm@plt>
   0x00000000004406ce <+254>:	mov    %rax,%rdi
   0x00000000004406d1 <+257>:	mov    %rax,%rbp
   0x00000000004406d4 <+260>:	call   0x4162c0 <_ZN4sigc9trackableC2Ev@plt>
   0x00000000004406d9 <+265>:	mov    $0x43fc90,%rax
   0x00000000004406e0 <+272>:	mov    %rbp,%rsi
   0x00000000004406e3 <+275>:	movq   $0x0,0x8(%rbp)
   0x00000000004406eb <+283>:	mov    %r13,0x48(%rbp)
   0x00000000004406ef <+287>:	mov    0x7b83a(%rip),%rdx        # 0x4bbf30
   0x00000000004406f6 <+294>:	mov    %r13,%rdi
   0x00000000004406f9 <+297>:	mov    %rax,0x10(%rbp)

Waybar 0.9.5 I have multiple monitors and some are connected with MST (displayport daisychain) and they dont all come back at once.