As a site administrator, when accessing the statistics plugin -> disk usage and choosing to display the disk usage per project, an error 502 is displayed.

In Nginx logs, we have something like:

FastCGI sent in stderr: "PHP message: PHP Notice:  Error encountered while retrieving data ==> SELECT SQL_CALC_FOUND_ROWS group_id, group_name, end_size, start_size, (end_size - start_size) as evolution, (end_size-start_size)/start_size as evolution_rate FROM (SELECT group_id, service, sum(size) as start_size
                       FROM plugin_statistics_diskusage_group
                       WHERE 1
                       AND  service IN ('svn','cvs','frs','ftp','grp_home','wiki','mailman','plugin_webdav','plugin_docman','plugin_git','plugin_svn','tuleap-gitlfs','plugin_mediawiki') group by group_id) as start LEFT JOIN (SELECT group_id, service, sum(size) as end_size
                       FROM plugin_statistics_diskusage_group
                       WHERE 
                       AND service IN ('svn','cvs','frs','ftp','grp_home','wiki','mailman','plugin_webdav','plugin_docman','plugin_git','plugin_svn','tuleap-gitlfs','plugin_mediawiki') group by group_id) as end USING (group_id) LEFT JOIN `groups` USING (group_id) Grou...