PHPUnit "Fatal error" during a test run in CI

A PHP fatal error (uncaught Error, type error, missing class) raised while a test executes can crash the PHPUnit process itself, so the run aborts mid-suite instead of recording a single failed test. The fatal in the bootstrap or app code is the real problem.

What this error means

PHPUnit stops partway with "PHP Fatal error: ..." and an incomplete summary, sometimes leaving the suite without a clean pass/fail. The fatal points at app or test code, not an assertion.

composer

PHPUnit 10.5.0 by Sebastian Bergmann and contributors.

..PHP Fatal error:  Uncaught TypeError: App\Money::__construct():
Argument #1 ($amount) must be of type int, string given, called in
/app/tests/MoneyTest.php on line 19

Common causes

An uncaught fatal in app or test code

A TypeError, undefined method, or missing class throws a fatal during a test, crashing the PHP process running PHPUnit.

A broken bootstrap or fixture

The PHPUnit bootstrap file or a fixture errors out, taking the whole run down before tests can be isolated.

How to fix it

Reproduce and read the fatal

Run PHPUnit with full error display and a single failing test to isolate the fatal.
Fix the underlying TypeError/missing class/method in app or test code.
Re-run the full suite.

Run with verbose error reporting

Surface the exact fatal location so it is not hidden by the crash.

Terminal

php -d display_errors=1 -d error_reporting=E_ALL \
  vendor/bin/phpunit --filter MoneyTest

How to prevent it

Keep strict types and signatures consistent so TypeErrors surface in development.
Validate the PHPUnit bootstrap and fixtures so a broken setup does not crash the suite.
Run the suite locally before pushing to catch fatals early.