udev fails to settle

I’ve been trying to get a BBB to boot from NFS with an overlay added
on the kernel command line with capemgr.enable_partno. However, udev
keeps timing out waiting for the udev queue, after calling settle.
The first uncompleted udev event is mostly for:
but it seems to stall on other devices as well.

If I don’t add the overlay, or use an local (USB) root file system,
then udev works correctly. Has anyone seem this before, or know
what the cause might be?

Thanks - Will

Show us your uEnv.txt file. Also, serial debug output would be handy. Which kernel version ? Which distro(Ubuntu ? ) ? Output from dmesg | grep udev if applicable.