When viewing http://upgrade.moodle.org/tag/index.php?tag=guinness, there are multiple:

Did you remember to make the first column something unique in your call to get_records? Duplicate value '1' found in column 'id'.

• line 741 of /lib/dml/mysqli_native_moodle_database.php: call to debugging()
• line 949 of /tag/lib.php: call to mysqli_native_moodle_database->get_records_sql()
• line 458 of /tag/lib.php: call to tag_get_correlated()
• line 106 of /tag/locallib.php: call to tag_get_related_tags()
• line 93 of /tag/index.php: call to tag_print_description_box()

It is important that we be able to easily find all the Guinness drinkers in the community! Peace - Anthony