# Django 2.2.9.dev20191202104323 文档

# Django 1.7.5 release notes

February 25, 2015

Django 1.7.5 fixes several bugs in 1.7.4.

## Bugfixes

- Reverted a fix that prevented a migration crash when unapplying `contrib.contenttypes`’s or `contrib.auth`’s first migration (#24075) due to severe impact on the test performance (#24251) and problems in multi-database setups (#24298).
- Fixed a regression that prevented custom fields inheriting from `ManyToManyField` from being recognized in migrations (#24236).
- Fixed crash in `contrib.sites` migrations when a default database isn't used (#24332).
- Added the ability to set the isolation level on PostgreSQL with psycopg2 ≥ 2.4.2 (#24318). It was advertised as a new feature in Django 1.6 but it didn't work in practice.
- Formats for the Azerbaijani locale (`az`) have been added.