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KDE uses an unreasonable amount of cache in /var/tmp/kdecache-$USER. Is there a way to limit the size of that cache instead of cleaning it manually from time to time? I do not have seen an option and Google is not my friend on this point.
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You could change /var/tmp to a directory in a larger partition like $HOME/.cache if you have a partition for /home, or somewhere else where there is more space available.
Apparently the KDEVARTMP environment variable can be used for that.
See KDE Filesystem Hierarchy
and KDE Environment Variables
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