“Login disabled” is not checked. I added some log entries replacing actual user name with “newusername”. Current log setting is “Trace”.
gitea.log
2018/04/26 12:08:34 [D] Session ID: c2c130cdd9894bad
2018/04/26 12:08:34 [D] CSRF Token: V_rQ_STcnHl4prIFYc1rJkGSS5U6MTUyNDc2Mzc3NTU1ODE3NTI1Mw==
2018/04/26 12:08:34 [D] Template: user/auth/signin
2018/04/26 12:08:34 [I] Failed authentication attempt for newusername
xorm.log
2018/04/26 12:08:34 [I] [SQL] SELECT `id`, `type`, `name`, `is_actived`, `is_sync_enabled`, `cfg`, `created_unix`, `updated_unix` FROM `login_source` WHERE (is_actived = ? and type = ?) []interface {}{true, 6}
2018/04/26 12:08:34 [I] [SQL] SELECT `id`, `lower_name`, `name`, `full_name`, `email`, `keep_email_private`, `passwd`, `login_type`, `login_source`, `login_name`, `type`, `location`, `website`, `rands`, `salt`, `created_unix`, `updated_unix`, `last_login_unix`, `last_repo_visibility`, `max_repo_creation`, `is_active`, `is_admin`, `allow_git_hook`, `allow_import_local`, `allow_create_organization`, `prohibit_login`, `avatar`, `avatar_email`, `use_custom_avatar`, `num_followers`, `num_following`, `num_stars`, `num_repos`, `description`, `num_teams`, `num_members`, `diff_view_style` FROM `user` WHERE `lower_name`=? LIMIT 1 []interface {}{"newusername"}