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
26180	Altering unique_together still sometimes missing deleted fields	Julian Andrews	Akshesh Doshi	"This is likely a missed edge case from #23614.

Steps to reproduce:

1. Create an app `spam`
2. Create a model `Spam`
{{{
class Spam(models.Model):
    a = models.CharField(max_length=255)
    b = models.CharField(max_length=255)
    c = models.CharField(max_length=255)

    class Meta:
        unique_together = (
            ('a', 'b'),
            ('b', 'c'),
        )
}}}
3. Make migrations
4. Delete field `Spam.c`
5. Delete the second `unique_together` constraint (`('b', 'c')`)
6. Make migrations
7. Run migrations

Output:
{{{
django.core.exceptions.FieldDoesNotExist: Spam has no field named u'c'
}}}
Note that the bug doesn't occur if no `unique togther` constraints remain.

Manually reversing the order of the operations in the migration (to remove the index first) produces a functional migration."	Bug	closed	Migrations	1.9	Normal	duplicate			Accepted	1	1	1	0	0	0