Segfault in gtk_window_new - c

Question

I have a simple GTK app written in C that segfaults on the line window = gtk_window_new(GTK_WINDOW_TOPLEVEL)
Here is the code:
#include <gtk/gtk.h>
int main(int argc, char **argv) {
GtkApplication *app = NULL;
GtkWidget *window = NULL;
app = gtk_application_new("com.github.Toothless204", G_APPLICATION_FLAGS_NONE);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_application_add_window(app, GTK_WINDOW(window));
int status = g_application_run(G_APPLICATION(app), argc, argv);
g_object_unref(app);
return status;
}
I have googled around to find an answer but didn't find anything that actually provided an answer as to what the problem could be

Answer 1

Problem: tried to create a window before the GTK+ initialization functions was called by the GtkApplication.
Before using GTK+, you need to initialize it.
https://developer.gnome.org/gtk3/stable/gtk3-General.html
#include <gtk/gtk.h>
int main(int argc, char **argv) {
GtkWidget *window = NULL;
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_widget_show (window);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_main_quit), NULL);
gtk_main();
return 0;
}
For the same reason GtkApplication windows must be added after the GApplication 'startup' signal has been emitted.
https://wiki.gnome.org/HowDoI/GtkApplication
#include <gtk/gtk.h>
static void activate (GApplication *app, gpointer user_data) {
GtkWidget *window;
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_application_add_window(GTK_APPLICATION(app), GTK_WINDOW(window));
gtk_widget_show (window);
}
int main (int argc, char **argv) {
GtkApplication *app;
int status;
app = gtk_application_new ("com.github.Toothless204", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}