[arch-general] [aur-general]WIKI/pacman -Sy

[Dennis Herbrich]

On Wed, Jun 27, 2012 at 03:56:25PM +0200, Arno Gaboury wrote:
> On the *pacman WIKI*, there is a useful Warning:
> **When installing packages, do *not* refresh the package list
> without upgrading
> <https://wiki.archlinux.org/index.php/Pacman#Upgrading_packages> the
> system (i.e. |pacman -Sy /package_name/|); this can lead to
> dependency issues.
> 
> But on most WIKI, when installing a new package is needed, I always
> find this command:
> 
> *$pacman -S packagenam*
> 
> As by definition WIKI will often adress to newbies, my thought was
> to replace whenever I find the above command by this following one:
> 
> *$pacman -Sy packagenam*

This is exactly what is advised against!

Rule of thumb:
DO NOT run "pacman -Sy <packages>", ever.
DO run "pacman -Syu ; pacman -S <packages>" instead,
if you want to have the latest and greatest <packages>.

pacman -Sy only updates your repository database, but NOT the packages on your
system. That way you will be presented with the *current* version of
<packages>, not those versions which would be correct for the state of your
system.
By just using pacman -S, you do NOT touch the repository database, so
you'll be getting potentially "old" packages that DO fit the rest of your
system, but you might experience the issue that the remote mirror does not
offer the old version anymore for download.
THEN you should upgrade the whole system and your repo database before
installing the package you want (-Syu), or download the missing package from
the the arch rollback machine and keep the "old" repo db.

HTH,
  Dennis

-- 
"Den Rechtsstaat macht aus, dass Unschuldige wieder frei kommen."
  Dr. Wolfgang Schäuble, Bundesinnenminister (14.10.08, TAZ-Interview)

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