Unit test time limit is per class, causes gradebook unit tests to sometimes fail

Exception: lib/grade/simpletest/testgradecategory.php / ? grade_category_test / ? test_grade_category_construct
Unexpected exception of type [ddl_exception] with message [XML database file errors found] in [/fs2/www/html/sm449/coremoodle/lib/ddl/database_manager.php line 390]

Debug info:

Errors found in XMLDB file: XML Error: Opening and ending tag mismatch: secondtag line 0 and wrongtag at line 4.

• line 425 of /lib/ddl/database_manager.php: call to database_manager->load_xmldb_file()
• line ... of ...
• line 80 of /lib/simpletest/fixtures/gradetest.php: call to UnitTestCaseUsingDatabase->create_test_tables()
• line ... of ...

Exception: lib/grade/simpletest/testgradecategory.php / ? grade_category_test / ? test_grade_category_build_path
Unexpected exception of type [ddl_exception] with message [XML database file errors found] in [/fs2/www/html/sm449/coremoodle/lib/ddl/database_manager.php line 390]

Debug info:

Errors found in XMLDB file: XML Error: Opening and ending tag mismatch: secondtag line 0 and wrongtag at line 4.

• line 425 of /lib/ddl/database_manager.php: call to database_manager->load_xmldb_file()
• line ... of ...
• line 80 of /lib/simpletest/fixtures/gradetest.php: call to UnitTestCaseUsingDatabase->create_test_tables()
• line ... of ...

... and many more