Some time ago (31 Oct 2008) I renamed perl-core/File-Spec-3.2701 to perl-core/File-Spec-3.27.01 by adding the new file and removing the other.
I expected portage to do an downgrade. It didn't. I realised it when i got this bug <https://bugs.gentoo.org/248178> and after joining #-portage I add a mask for a non-existing package to package.mask. Today I was CC'ed to https://bugs.gentoo.org/105016 because "package.mask contains invalid entries". In the meantime another bug was filed about portage "doesn't attempt to downgrade packages on keyword changes..." <https://bugs.gentoo.org/252167> with a fix. I am confused. Will portage warn about the downgrade now and forever?