The default for _PHPUNIT_CONCURRENT has changed from 0 to 1

PHPUnit jobs now default to use core’s run-tests.sh script by default (documentation). This has been is achieved by altering the default for the variable _PHPUNIT_CONCURRENT from 0 to 1.

This option has been available for a long time and is documented here. We changed the default because run-tests.sh is much more performant than the phpunit binary. The same number of tests can be run 3 to 5 times faster, therefore reducing the total pipeline time and reducing the number of CI minutes spent on test runs.

In most cases, a green pipeline with phpunit should still produce a green pipeline with run-tests.sh. If you have customizations around this, you might see a warning to adapt the variable names.

If you still want to continue using phpunit binary to run the tests, all you need to do is set the variable _PHPUNIT_CONCURRENT to 0, although we recommend using the new default value, which is 1.

If you didn't have any customizations, the same number of tests should run, and the result should be the same.

If you were using phpunit as the test runner and you had customizations:
Before

  _PHPUNIT_EXTRA: "...options here for phpunit..."

After

  _PHPUNIT_CONCURRENT: 0
  _PHPUNIT_EXTRA: "...options here for phpunit..."

If you were using run-tests.sh as the test runner and you had customizations:
Before

  _PHPUNIT_CONCURRENT: 1
  _PHPUNIT_EXTRA: "...options here for run-tests.sh..."

After

  _PHPUNIT_CONCURRENT: 1 (optional)
  _RUNTESTS_EXTRA: "...options here for run-tests.sh..."