Tests fail but build is still "success"

Hello,

We’ve been using docker-compose to run our tests since switching to CircleCI a year ago. It’s always returned the expected non-zero exit code on failure…until last week. Starting last week, all failing tests have been marked as “success”, and we only realized that today. CircleCI now reports “Exit Code: 0” when the tests fail.

The line that runs our tests is:

docker-compose -f docker-compose.test.yml run --name=phpunit --no-deps php php vendor/phpunit/phpunit/phpunit

It was last changed 2/15/2016.

Can someone look into this?