MarsSeed [1] filed a deletion request for tomcat8-solr [2]: Unused tomcat8 config package from 2015 for solr v4.10.3, which is a version that does not exist in repo, only solr 9.4.x.
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/tomcat8-solr/
