I tried to emerge mediawiki with the mysql use flag set. I already have mysql-community installed. I get this: 

[ebuild  N     ] dev-db/mariadb-10.4.6:0/18::core-server-kit  USE="backup cracklib extraengine perl server xml -bindist -client-libs -debug -galera -innodb-lz4 -innodb-lzo -innodb-snappy -jdbc -jemalloc -kerberos -latin1 -libressl -mroonga -numa -odbc -oqgraph -pam -profiling -rocksdb (-selinux) -sphinx -sst-mariabackup -sst-rsync -static -systemd -systemtap -tcmalloc -test -tokudb -yassl" 75,237 KiB

[ebuild  N     ] virtual/mysql-5.6-r12:0/18::core-server-kit  USE="server -embedded -static" 0 KiB

[ebuild  N     ] www-apps/mediawiki-1.32.2:1.32.2::net-kit  USE="imagemagick mysql vhosts -postgres -sqlite" 35,341 KiB

[blocks B      ] dev-db/mariadb ("dev-db/mariadb" is blocking dev-db/mysql-community-8.0.16)

What seems to be happening is that virtual mysql is not recognizing that mysql-community is mysql and is incorrectly insisting that I install maria-db. 

get this