Code coverage is always unknown in GitLab - unit-testing

Question

I'm trying to understand the GitLab Pipelines and after a few tries I was able to successfully automate my unit tests. Now I'm trying to add the code coverage badge into my project and/or readme file but it always seems to show unknown.
Files:
+ application
+ system
- unit-tests
- tests
UtilTest.php
autoload.php
phpunit
.gitignore
.gitlab-ci.yml
.htaccess
index.php
readme.md
.gitlab-ci.yml:
image: php:5.6
stages:
- test
app:unit-tests:
stage: test
script:
- php ./unit-tests/phpunit --bootstrap ./unit-tests/autoload.php ./unit-tests/tests
coverage: '/Code Coverage: \d+\.\d+/'
On the project's Test coverage parsing section I have this set up:

Answer 1

So I was able to fix this by using PHP 7.2 as the Docker image and installing xdebug on the before_script call.
.gitlab-ci.yml:
image: php:7.2
stages:
- test
before_script:
- pecl install xdebug
- docker-php-ext-enable xdebug
app:unit-tests:
stage: test
script:
- php ./unit-tests/phpunit --bootstrap ./unit-tests/autoload.php ./unit-tests/tests --coverage-text --colors=never
coverage: '/^\s*Lines:\s*\d+.\d+\%/'
I had to use PHP 7.2 because when I tried running pecl install xdebug it said it requires PHP 7. Ideally I would like to use PHP 5.6 because that's what our current server has just so the tests are on similar versions but I'll leave it as it is for now.
I had to add --coverage-text --colors=never on the script call for it to output the numbers. Then on the coverage call I changed it to '/^\s*Lines:\s*\d+.\d+\%/' which I also used under the Test coverage parsing section on the project settings.
And now the code coverage properly shows me my expected values.