Thanks for the suggestion Renaat, but I only have one version of PHP installed, and it displays correctly via php -v and on the Moodle page.

When I look at what generates this error, it appears to be if the database and moodledata were not created with the same version of Moodle you are trying to run the unit tests from. However, I get the error on a totally fresh install of 3.6, where the database and data are most definitely created by that version of Moodle. The same server runs the unit tests in a 3.4 installation just fine.

When I run the init.php script, nothing is put into the /moodledata/phpunit directory, which is where the library looks to do the comparison to run the unit tests. I'm wondering if there isn't an issue with the init script in 3.6 (and sounds like 3.5 for Koray above). I submitted a tracker issue, but was told it is not a bug .