@Vrakfall: I don't know exactly what the idea behind the version check is, the package arrived this way from the community/ repo. :)
Yes, I checked and it works with Perl 5.28, not sure if it needs a rebuild but most probably it does.
Concerning bumping the pkgrel on perl updates, see this discussion: https://forum.manjaro.org/t/aur-install-packages-with-perl-broken-again/30913/4
Pinned Comments
bidulock commented on 2021-03-26 00:14 (UTC)
https://gist.github.com/bbidulock/5fe3d829b8210e50a606dc9cfd145962
A PKGBUILD for libunique.
PhotonX commented on 2018-08-06 13:17 (UTC) (edited on 2018-08-06 13:19 (UTC) by PhotonX)
In case that perl-gtk2-unique prevents the perl update to 5.28, please remove perl-gtk2-unique
pacman -Rdd perl-gtk2-unique
then do the update and then install it again
$YOUR_FAVORITE_AUR_HELPER -S perl-gtk2-unique
In case there is a better solution, please let me know! :)