Offscreen rendering hangs RSP about libdragon HOT 4 CLOSED

#include <libdragon.h>

static surface_t zbuffer;
static unsigned int counter = 0;

static void draw(void) {
  rdpq_clear(RGBA32(0, 0, counter & 255, 255));
  rdpq_clear_z(0xfffc);
  rdpq_mode_begin();
  rdpq_set_mode_standard();
  rdpq_mode_zbuf(true, true);
  rdpq_mode_end();
  rdpq_mode_combiner(RDPQ_COMBINER_FLAT);
  rdpq_set_prim_color(RGBA32(255, 0, 0, 255));
  const float vs[][3] = { { 20, 20, 0 }, { 50, 20, 1 }, { 20, 40, 0.5 } };
  rdpq_triangle(&TRIFMT_ZBUF, vs[0], vs[1], vs[2]);
  counter++;
}

static void draw_offscreen(void) {
  surface_t *screen = display_get();
  surface_t buffer = surface_alloc(FMT_RGBA16, display_get_width(), display_get_height());

  rdpq_attach(screen, NULL);
    rdpq_attach(&buffer, &zbuffer);
      draw();
    rdpq_detach();
    rdpq_set_mode_standard();
    rdpq_tex_blit(&buffer, 0, 0, NULL);
  rdpq_detach_wait();

  surface_free(&buffer);
}

int main(void) {
  debug_init_isviewer();
  debug_init_usblog();
  controller_init();
  rdpq_init();
  rdpq_debug_start();
  rdpq_debug_log(true);

  display_init(RESOLUTION_640x480, DEPTH_16_BPP, 3, GAMMA_NONE, ANTIALIAS_OFF);
  zbuffer = surface_alloc(FMT_RGBA16, display_get_width(), display_get_height());

  surface_t *screen = display_get();
  rdpq_attach(screen, &zbuffer);
  draw();
  rdpq_detach_show();

  while (true) {
    controller_scan();
    struct controller_data pressed = get_keys_pressed();
    if (pressed.c[0].A)
      break;
  }

  while(true)
    draw_offscreen();

  return 0;
}

  display_init(RESOLUTION_640x480, DEPTH_16_BPP, 3, GAMMA_NONE, ANTIALIAS_OFF);
  zbuffer = surface_alloc(FMT_RGBA16, display_get_width(), display_get_height());

  surface_t *screen = display_get();
  rdpq_attach(screen, &zbuffer);
  draw();
  rdpq_detach_wait(); // RSP CRASH