Install package - don't update other packages

I’m often using slow internet connections. Sometimes they are even expensive to use (pay per MB). For that reason I don’t want ANY automatic updates. In the default program called “Add/Remove software” I went to preferences and set the following:
General - Check for updates = off
Advanced - Do not check for updates when installing = on
Still, it does update everything when I install something new. Like right now I wanted to install wmctrl, a package of 46,4kB. This installation resulted in a 848MB download of updates. Not a big issue today as I’m on a fast connection, but I want to be in control of this. How can I install a package without getting updates for everything else?

I am afraid it is in the GUI “Install/remove software” not possible, but on the command line you can do this:

pacman -S <package>

but yes @cscs is right, it is recommended to only install new software if your system is updated.

Partial upgrade = Broken system


Is “install something new” equal to “partial upgrade”?

Installing an application will always try to get the last version of the package, the one is the repository.
In order to work correctly, a package requires its dependencies to also be at the latest version. As well those packages’ dependencies, and so on.
But those updated dependencies may also be dependencies to other packages, which you haven’t updated; and those may break because they don’t use the relevant version.
Thus, the simplest way to keep your system stable when installing an application is to stay up-to-date.

I see. Is there a way to upgrade dependencies only if the installed version of dependencies is not good enough?
With Gentoo, minimum (and/or maximum) version number of the dependent package is listed in the dependency list.

The only way as I see it is if you could find versions of the required packages from about the same date as your last system upgrade.

Otherwise it might be better to dual-boot with a point-release distro & use that for testing out packages … or, see if there is e.g. an AppImage or Flatpak version.