Translations:ACCEPT KEYWORDS/3/en
From Gentoo Wiki
The default value of most profiles' ACCEPT_KEYWORDS variable is the architecture itself, like amd64 or arm. In these cases, the package manager will only accept ebuilds whose KEYWORDS variable contains this architecture. If the user wants to be able to install and work with ebuilds that are not considered production-ready yet, they can add the same architecture but with the ~ prefix to it, like so: