The MineOS plugin installation currently fails due to an issue with the git-lite package.
Install Error: mineos-jail had a failure Exception: RuntimeError Message: pkg error: - devel/git-lite : Refusing to fetch artifact and run post_install.sh! Partial plugin destroyed
The reason is that the git-lite package was converted from a "slave" port to a "flavor" of the git port. As a result pkg install devel/git-lite no longer works for some reason, but pkg install git-lite without the category works fine.
I'll submit a PR with a fix/workaround. This bug is to track the issue.