It looks like we don't support SELinux label inside chroot.  Note the goal is NOT to "enable" SELinux to chroot.

$ stat -c '%C' ~/.gitconfig
stat: failed to get security context of '/home/victorhsieh/.gitconfig': Operation not supported

As vapier@ mentioned, we probably just need USE=selinux for tool support.  Probably no file system change is needed, as extended attribute is already supported.