Inconsistencies with dnf needs-restarting

[grumpey]

dnf5 version 5.2.17.0
dnf5 plugin API version 2.0
libdnf5 version 5.2.17.0
libdnf5 plugin API version 2.2

name: needs_restarting
version: 1.0.0
API version: 2.0

Fedora 43

This sometimes works and sometimes does not.
What works:
dnf needs-restarting
dnf needs-restarting --services
sudo -E dnf needs-restarting

What doesn't always work:
sudo dnf needs-restarting
sudo dnf needs-restarting --services
sudo dnf needs-restarting --reboothint

When the command with sudo fail, running without sudo functions correctly.

What doesn't work:
sudo -E dnf needs-restarting --services
It returns [System.Error.ENOTCONN] Failed to flush bus on opening (Transport endpoint is not connected)
Similar to: https://bugzilla.redhat.com/show_bug.cgi?id=2419668

Also filed: https://bugzilla.redhat.com/show_bug.cgi?id=2428601

[pkratoch]

Thanks for the report. The issue is valid, it can be also reproduced with:

su -
dnf needs-restarting --services

But not with:

su root
dnf needs-restarting --services

It's not about running the command as a superuser, but rather that the session is not created properly. Notably, the environment variables DBUS_SESSION_BUS_ADDRESS and XDG_RUNTIME_DIR are not defined when running su -. Defining any one of them is sufficient for the dnf needs-restarting --services to succeed, though that by itself probably wouldn't be a sufficient fix. From the documentation of su -: "Note that on systemd-based systems, a new session may be defined as a real entry point to the system. However, su does not create a real session (by PAM) from this point of view. You need to use tools like systemd-run or machinectl to initiate a complete, real session."