river-tag-overlay.c: In function 'render_frame':
river-tag-overlay.c:262:3: error: 'fd' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  262 |   close(fd);
      |   ^~~~~~~~~
river-tag-overlay.c:219:6: note: 'fd' was declared here
  219 |  int fd = -1;
      |      ^~