g_list_store_find_with_equal_func is not binding friendly
The function has the following signature
gboolean
g_list_store_find_with_equal_func (GListStore *store,
gpointer item,
GEqualFunc equal_func,
guint *position);
Functions that takes a callback/another function in parameter, usually takes a user_data to allow language bindings to pass in the trampoline function.
This was originally reported for rust bindings at https://github.com/gtk-rs/gtk-rs-core/issues/202 & https://github.com/gtk-rs/gtk-rs-core/pull/205 for details.