When a PHPUnit test fails normally on my dev box (Linux Mint), it causes a "Segmentation Fault" on my Continous Integration box (Centos). Both machines are running the same version of PHPUnit. My dev box is running PHP 5.3.2-1ubuntu4.9, and the CI is PHP 5.2.17. I'd rather leave upgrading the PHP as a last resort though.
As per this thread: PHPUnit gets segmentation fault
I have tried deactivating / reinstalling Xdebug. I don't have inclue.so installed.
On the CI box I currently only have two extensions active: dom from php-xml (required for phpunit) and memcache (required by my framework), all the others have been turned off.
Next to what cweiske suggested, if upgrading PHP is not an option for you and you have problems to locate the source of the segfault, you can use a debugger to find out more.
You can launch gdb this way to debug a PHPUnit session:
gdb --args php /usr/bin/phpunit quiz_service_Test.php
Then type in
r to run the program and/or set environment variables first.
set env MALLOC_CHECK_=3 r
You might also consider to install the debugging symbols for PHP on the system to get better results for debugging. gdb checks this on startup for you and leaves a notice how you can do so.