PHP 7.1 pre-installed PHPUnit version 8 is broken

I’m running a php 7.1 build on Xenial. It fails before my script is actually executed:

Setting up build cache

$ php --version
PHP 7.1.27 (cli) (built: Mar 13 2019 07:54:47) ( ZTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.1.27, Copyright (c) 1999-2018, by Zend Technologies
    with Xdebug v2.7.0, Copyright (c) 2002-2019, by Derick Rethans
$ composer --version
Composer version 1.9.3 2020-02-04 12:58:49

$ phpunit
PHPUnit 8.0.4 by Sebastian Bergmann and contributors.

This version of PHPUnit is supported on PHP 7.2 and PHP 7.3.
You are using PHP 7.1.27 (/home/travis/.phpenv/versions/7.1.27/bin/php).
The command "phpunit" exited with 1.

It’s due to PHPUnit8 being globally installed but not supported on php 7.1. This is the build system information:

Build language: php
Build group: stable
Build dist: xenial
Build id: 648629816
Job id: 648629817
Runtime kernel version: 4.15.0-1028-gcp
travis-build version: 08047b878
Build image provisioning date and time
Mon Mar 25 16:43:24 UTC 2019
Operating System Details
Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.6 LTS
Release:	16.04
Codename:	xenial

As this is outside client control it would need to be fixed on the travis image. Here’s an actual build example:

Is this the right place to get help with this?

Same problem here. The 7.1 image is broken- it MUST not install PHPUnit 8