Theo de Raadt <deraadt@openbsd.org> wrote:

> +++ distrib/miniroot/install.sub
> @@ -1807,6 +1807,10 @@ install_files() {
>                 rm -rf /mnt/var/syspatch/*
>         fi
> 
> +       # Transition font cache ownership from root to its dedicated user.
> +       # XXX Remove after 7.9 release.
> +       chown -R _fc-cache:_fc-cache /mnt/var/cache/fontconfig
> +
>         # Install the set files.
>         for _f in $_get_sets; do
>                 reset_watchdog
> 
> I don't think this can be removed for a long time, because sysupgrade
> -R allows for quite arbitrary jumps between release builds.

In particular note that if you go bakwards with sysupgrade:

     -R version
             Upgrade to a specific release version.  Only upgrades from one
             version to the next are tested.  Skipping versions may work.
             Downgrading is unlikely to work.

For an older release, the upgrade directory will become owned by root because
that is what the X sets say.  The tools will behave as root.  The ports tree
will behave as root.  However, some older files from packages, in the directory
will not be be replaced, and therefore be owned by the new user.  I suspect
the tools will work OK with that, because they are running as root.

The problem really arises if you upgrade from 7.7 to 8.2 in one step.
Sure, the -R documentation says this may not work.  But the situation is a
bit more difficult.  It WILL NOT EVER WORK WELL moving into the future, if
you delete that chown.  That's a bit harsh.  We would need to modify the -R
documentation to say "Skipping versions will not work".

I recommend you change your comment to:

> +       # From 7.8 onwards, fontcache isn't owned by root
> +       chown -R _fc-cache:_fc-cache /mnt/var/cache/fontconfig