Upgrader tool with PHP 7.3

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

Silverstripe Version: 3.7.3

Question:

I’ve run into a problem when trying to upgrade from Silverstripe 3.7.3 to 4.x. I’m using the Silverstripe Upgrade tool. Our existing codebase uses PHP 7.3, and includes some code features that are new in PHP 7.3.

It seems that the upgrade tool does not support PHP 7.3. I think the dependencies on nikic/php-parser and phpstan/phpstan (and quite possibly others) will need to be updated for PHP 7.3 support.

Has anyone run into this problem before? Any work arounds?

I am trying to upgrade from SS3 to SS4 me too, but i get same error on PHP.