id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
26643	AlterModelManagers migration is generated for all Models with custom Managers pointing to the default Django Manager	Anthony King	Matthew Schinckel	"Working on a project with Models written with migrations generated by Django 1.8 (upgraded to 1.9), when running `makemigrations`, some unexpected migrations were generated.

{{{#!python
...
migrations.AlterModelManagers(
    name='some_model',
    managers=[
        ('objects', django.db.models.manager.Manager()),
    ],
),
}}}

We've never run `AlterModelManagers` in the past. Instead of the Manager we define being added, the default Manager is being set.

I can add code examples + instructions later"	Bug	closed	Migrations	1.10	Release blocker	fixed		Loic Bistuer	Ready for checkin	1	0	0	0	0	0