drupal8 SCM istallation via web fails in absence of php56-tokenizer module. This module is listed as a dependency for www/drupal8 in [1]

However, php56-tokenizer is not automatically installed when drupal8 is installed via pkg(8). 

In addition to php56-tokenizer, php56-opcache, which is a recommended module by drupal, is also not installed when the software installation is performed via pkg(8).

Below is a demonstration of the problem;

root@port-test:~ # uname -a
FreeBSD port-test 11.1-RELEASE FreeBSD 11.1-RELEASE #0 r321309: Fri Jul 21 02:08:28 UTC 2017     root@releng2.nyi.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64
root@port-test:~ # pkg install drupal8

Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
All repositories are up to date.
The following 19 package(s) will be affected (of 0 checked):

New packages to be INSTALLED:
	drupal8: 8.3.5
	php56-session: 5.6.31
	php56: 5.6.31
	php56-xml: 5.6.31
	php56-simplexml: 5.6.31
	php56-dom: 5.6.31
	php56-hash: 5.6.31
	php56-filter: 5.6.31
	php56-gd: 5.6.31
	t1lib: 5.1.2_4,1
	php56-json: 5.6.31
	php56-pdo_mysql: 5.6.31
	php56-pdo: 5.6.31
	php56-mysql: 5.6.31
	mysql56-client: 5.6.37
	libevent: 2.1.8
	liblz4: 1.7.5,1
	php56-mbstring: 5.6.31_1
	oniguruma6: 6.4.0

Number of packages to be installed: 19

The process will require 117 MiB more space.
15 MiB to be downloaded.

Proceed with this action? [y/N]: y

...
these lines have been removed
...

root@port-test:~ # pkg info | grep tokenizer 
root@port-test:~ # pkg info | grep opcache

[1] https://www.freebsd.org/cgi/ports.cgi?query=drupal8&stype=all