On Sun 18 Mar 2018 at 19:13:04 +0100, Jonas Smedegaard wrote: > Quoting Brian Potkin (2018-03-18 19:00:20) > > During the management of bug #891810 this exchange took place between > > Jonas Smedegaard and Didier 'OdyX' Raboud: > > > > Le dimanche, 4 mars 2018, 13.54:27 h CET Jonas Smedegaard a écrit : > > > > Is PolicyKit _required_ for _all_ uses of hplip? > > > > > Good question. I'll admit I was put off my the (exhausting) 'systemd' > > > argument, and hadn't checked what exactly was done with PolicyKit. > > > > > My reading is that PolicyKit is used to grant privilege to run > > `hp-plugin` for > > > plugin download, thereby avoiding the need for sudo. > > > > > So no, definitely not _required_. > > > > I thought that is the function of Policykit in hplip too so put it to > > the test yesterday. stretch (base system only) was installed, upgraded > > to unstable and then hplip (without its recommended packages) was > > installed. 'hp-plugin -i' runs to completion after asking for and being > > provided with the root/superuser password. There is no difference in the > > outcome when policykit-1 is on the system. > > > > Maybe policykit-1 is used elsewhere with hplip (the GUI parts?) but I > > did not look at this extensively. What I did do was use 'hp-setup -i' > > without policykit-1 for a USB connected MFP. That gave > > > > error: No device selected/specified or that supports this functionality > > > > and journalctl indicated that permission to access the USB bus had been > > denied. Easily solved (as it is when sane-find-scanner gives a negative > > outcome) by installing libpam-systemd. (Or, interestingly, putting the > > user in the scanner group). > > > > The small amount I did indicates that having policykit-1 as only a > > Recommends: has not impacted unfavourably on the hplip package. > > Thanks for sharing those details. > > From what you quoted above, it seems that Didier already hinted that > (likely) the need for systemd was "for plugin download".
Note that neither of the two commands I used required policykit-1 to be on the system for them to run successfully. What I forgot to mention was that after installing libpam-systemd, the user has to log out and log in again, so, as a non-expert guess, logind is involved somewhere. I am not arguing for changing the present arrangement wrt dependencies but pointing out (assuming the testing is valid) that libpam-systemd seems to be the more important package when hp-setup is used. Regards, Brian.
