Trying to do a software update, the corresponding program "Software & Updates" got stuck during the cache refresh.
How can I kill such a process? I looked at all the running processes with
su, but I cannot find one with a name similar to the one I am looking for.
The interaction with the GUI (KDE) does not allow me to close the dialog (option disabled).
xkill is likely to work here. Just run the
xkill command in a terminal (which I assume you can do, since you mentioned trying
su), then click on the "Software & Updates" window.
xkill will forcibly close that window, which usually (but not always) triggers the underlying application to terminate.
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