Synfig Studio crashes on macOS 15.6.1 (Sequoia) shortly after startup

Hi,

I’m trying to run the official Synfig Studio macOS build on macOS 15.6.1 (Sequoia), to test a bug I found on the build I forked but it consistently crashes a few seconds after startup.

  • macOS: 15.6.1 (Sequoia)
  • Hardware: Apple Silicon arm64
  • Synfig Studio: official download from synfig.org

Behavior:

  • App launches normally.

  • It initializes subsystems and UI.

  • 15–20 seconds after using the app (interacting with it, clicking stuff inside etc.), it exits with status 11

  • No visible macOS crash dialog appears.

When run under lldb:

  • Process exited with status = 11 (0x0000000b)

Also get these when I run the official app :
(synfigstudio:33819): Gtk-WARNING **: Drawing a gadget with negative dimensions. Did you forget to allocate a size? (node header owner gtkmm__GtkNotebook)

(synfigstudio:33819): Gtk-WARNING **: Drawing a gadget with negative dimensions. Did you forget to allocate a size? (node tabs owner gtkmm__GtkNotebook)

(synfigstudio:33819): Gtk-WARNING **: Drawing a gadget with negative dimensions. Did you forget to allocate a size? (node tab owner gtkmm__GtkNotebook)

(synfigstudio:33819): Gtk-WARNING **: Allocating size to gtkmm__GtkWindow 0x7facd72a2520 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?

(synfigstudio:33819): Gtk-WARNING **: Allocating size to gtkmm__GtkNotebook 0x7facd774afe0 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?

(synfigstudio:33819): Gtk-WARNING **: Allocating size to gtkmm__GtkNotebook 0x7facd774afe0 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?

(synfigstudio:33819): Gtk-WARNING **: Allocating size to gtkmm__GtkNotebook 0x7facd774afe0 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?

2026-03-03 15:56:24.158800+0300 synfigstudio[33819:40823704] [CursorUI] -[TUINSCursorUIController activate:]: redesigned_text_cursor is disabled