Due to changes in how the FreeBSD port system handles the install target, certain ports fail to install with the error "pkg_create: make_dist: tar command failed with code 256" in Jails installed with the current version of ezjail. ezjail from version 3.4 fixes this. Until then you should execute the command mkdir -p /var/ports/packages as a workaround in all jails you want to install ports in.