i have been seeing this warning for months actually

<pre>
# pacman -Syu
....
WARNING: '/usr/lib/perl5/5.26' contains data from at least 1 packages which will NOT be used by the installed perl interpreter.
-> Run the following command to get a list of affected packages: pacman -Qqo '/usr/lib/perl5/5.26'
....

$ pacman -Qqo '/usr/lib/perl5/5.26'
perl-linux-desktopfiles
</pre>