Please depend on virtual/mysql instead of dev-db/mysql The mysql team will be supporting several forks. No ebuild should depend on one unless it requires a certain feature not available in others.
Seems there is no love here. After 30 days, I will commit this change to the ~arch version
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=7353a9cb9c319bfbd76e1ff531a176261ee647ff