Hi Sam,

When I run the unit tests with this commit '6553cda7c9b9d9ae5439a22841f7986c9b67bc36' , I get these errors:

set_module_viewed must be called before header is printed

• line 609 of \lib\completionlib.php: call to debugging()
• line 255 of \lib\simpletest\testcompletionlib.php: call to completion_info->set_module_viewed()
• line 72 of \lib\simpletestlib\invoker.php: call to completionlib_test->test_set_module_viewed()
• line 137 of \lib\simpletestlib\invoker.php: call to SimpleInvoker->invoke()
• line 53 of \lib\simpletestlib\errors.php: call to SimpleInvokerDecorator->invoke()
• line 137 of \lib\simpletestlib\invoker.php: call to SimpleErrorTrappingInvoker->invoke()
• line 43 of \lib\simpletestlib\exceptions.php: call to SimpleInvokerDecorator->invoke()
• line 148 of \lib\simpletestlib\test_case.php: call to SimpleExceptionTrappingInvoker->invoke()
• line 617 of \lib\simpletestlib\test_case.php: call to SimpleTestCase->run()
• line 620 of \lib\simpletestlib\test_case.php: call to TestSuite->run()
• line 37 of \admin\report\unittest\ex_simple_test.php: call to TestSuite->run()
• line 144 of \lib\simpletestcoveragelib.php: call to AutoGroupTest->run()
• line 100 of \admin\report\unittest\index.php: call to autogroup_test_coverage->run()

Let me know if you need more info. Thanks.