I saw this mentioned as another possible way forward:

https://github.com/illiliti/libudev-zero

The README is interesting.

The main problem seems to be that it still depends on udev, and is
therefore subject to any changes made in it. One criterion in deciding
which of the possibilities could be the best way forward would be the
degree of dependence on systemd/udev - the less dependence, the less
possibility of an upstream breaking change.

On Tue, 2021-09-14 at 00:26 +0300, Boian Bonev wrote:
> > Gentoo recently announced a decision to drop maintenance of the eudev
> package. [1]
>
> As long as eudev [2] is an essential component of distributions
> implementing init system diversity, there are several paths forward:
>
> - - continue maintaining eudev
> - - switch to udev from systemd
> - - switch to another alternative [3][4]
>
> After some discussion and research of the current alternatives, eudev
> seems to be the most mature and least risky option but will require
> ongoing maintenance.
>
> systemd's udev is not an option because it is clearly stated that there
> is no plan to keep it usable outside of systemd's environment. [5]
>
> Devuan has initiated an effort to bring together those interested in
> keeping eudev maintained on #devuan-eudev [6].
>
> We would like to invite all interested parties and/or individuals to
> join our effort.
>
> [1]
> https://www.mail-archive.com/gentoo-dev@lists.gentoo.org/msg93253.html
> [2]
> https://github.com/gentoo/eudev
> [3]
> https://wiki.gentoo.org/wiki/Mdev
> [4]
> http://judecnelson.blogspot.com/2015/01/introducing-vdev.html
> [5]
> https://github.com/systemd/systemd/pull/20596#issuecomment-910360057
> [6]
> ircs://irc.libera.chat:6697/devuan-eudev
>
> PS. Please also CC me in replies as I am not on the list
> >
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