No sure if this should be considered a bug or not.

If udevd is started without any fd, some of the fd created during setup will occupy fd 0, 1, 2. And they will be overridden by:

https://github.com/gentoo/eudev/blob/79f7650b59c4f9261b5e9e76e3c57cfc90b2dc6b/src/udev/udevd.c#L1293-L1295

cause udevd to loss those essential fds and fail.