The sandbox is designed to allow standard select&paste operation on
the text console. More fancy uses of gpm are unlikely to work, but
that's on purpose: the only thing that people should be using gpm for
is the occasional text copying when they land in rescue mode.
This serves as an alternative to [1]. The replacement policy is probably
stricter in some regards, while less strict in others… But I think it's
much less magic and should be easier to maintain.
[1] https://src.fedoraproject.org/rpms/gpm/pull-request/4