== Running Fedora 22's _dnf_ as a normal user versus as root

If you're me, you've probably done this at some point:

.pn prewrap on
>  # dnf clean metadata
>  [...]
>  # dnf check-update
>  [... lists some available updates ...]

Then in another window, running as myself:

>  ; dnf updateinfo info
>  [... doesn't report anything ...]

Wait, what?

What's going on here is that ~~_dnf_ maintains separate package
databases for root and for individual users~~. When you run _dnf_
as root, it consults (and updates) the 'official' DNF package
databases and metadata under _/var/cache/dnf_. When you run _dnf_
as any non-root user, it uses a _/var/tmp/dnf-<user>-<random>_
directory instead; although everything in _/var/cache/dnf_ is
world-readable, dnf makes no attempt to look at it. As a result
it's completely possible for root's _dnf_ commands and your _dnf_
commands to give completely different results.

You can reduce the odds of this by remembering to do '_dnf clean
metadata_' or the like as yourself too, but this doesn't absolutely
guarantee that root's data and your data are in sync. When your
_dnf_ command re-pulls the package information, it may fetch it
from a different mirror that is more (or less) up to date than the
mirror root's _dnf_ used.

(And of course this wastes bandwidth on re-fetching data you already
have.)

I hate the idea of running '_dnf updateinfo info_' as root instead
of myself, but I'm probably going to have to get used to it. There
are just too many annoyances otherwise.

PS: Yes, I know about '_dnf clean expire-cache_'; I used to do it
all the time with yum. Unlike with yum, with DNF it doesn't work
really well to get me the latest update state. Have I mentioned
that [[I'm not fond of DNF Fedora22AndDNFImpressions]]?

=== Sidebar: How _dnf_ should behave

When run as a normal user, DNF should try to use _/var/cache/dnf_
data files if they're suitable, ie if they're sufficiently up to
date and DNF is being used in a mode where it only needs read access
to them. Only if DNF has been asked to do something that would
normally write to _/var/cache/dnf_ would it switch to the
_/var/tmp/dnf-<user>-..._ scheme. In other words, if you just used
information commands as a normal user you'd get to take advantage
of the system DNF database.