[systemd-devel] dependencies between instances

[Oleksii Shevchuk]

> Can you suggest other usecases?

I can. Situation like local client-server, where server requires root
creds, cannot into socket/d-bus activation and requires device or
something about it; client should be running from user and server
requires.

Example: pcscd + nfc-eventd

So, how it supposed to be working:

1. Device inserted
2. System-wide unit started
2.1. Deps of unit started
2.2. System instance makes announce about started unit
2.3  User instances gets announce
3. User instances makes this virtual unit active
4. User instances starts user configured deps of unit