turns out trying to access the position of a closed window results in an x error

who could've known

src/chatter_context.cr

@@ -40,7 +40,9 @@ class Funfriend::ChatterContext < Funfriend::WindowContext
   def update_position
     if parent
       p = parent.not_nil!
-      window.position = (Vec2.new(p.window.position) + Vec2.new(p.window.size) / 2 + parent_relative_pos - window_size / 2).xy_i
+      if !p.closed
+        window.position = (Vec2.new(p.window.position) + Vec2.new(p.window.size) / 2 + parent_relative_pos - window_size / 2).xy_i
+      end
     end
   end
 

src/window_context.cr

@@ -5,6 +5,7 @@ GLFW_FOCUS_ON_SHOW = 0x0002000C
 
 class Funfriend::WindowContext
   getter window : CrystGLFW::Window
+  property closed : Bool = false
 
   DEFAULT_HINTS = {
     # supposedly required on MacOS
@@ -43,6 +44,7 @@ class Funfriend::WindowContext
 
   def close
     window.destroy
+    @closed = true
   end
 
   def clean_up