Segmentation fault (core dumped) when running testsuite

I randomly (and often) receive a Segmentation fault (core dumped) error when running phpunit (version 6.4.1) on a testsuite inside ssh of homestead. When I run one unit test at a time or run a smaller suite, the tests all pass. The most memory any one of the tests use is 20.00 MB.

Outside ssh (PHPUnit version 6.2.3), the tests all run perfectly: OK (131 tests, 1876 assertions)

In each test, I use Illuminate\Foundation\Testing\DatabaseMigrations, running on a database connection:

'testing' => [
        'driver'   => 'sqlite',
        'database' => ':memory:',
        'prefix'   => '',
    ],

Should I be concerned at all about this? Is it just best practice to run phpunit outside of ssh? I don't want to update my PHPUnit and then find that I have to run my tests one by one.