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
31289	system checks: admin.E002 could provide a hint but doesn't	Keryn Knight	Sanskar Jaiswal	"Currently the output is:

{{{
myapp.MyCustomUserModel: (auth.E002) The field named as the 'USERNAME_FIELD' for a custom user model must not be included in 'REQUIRED_FIELDS'.
}}}

because I accidentally had:
{{{
USERNAME_FIELD = ""email""
EMAIL_FIELD = ""email""
REQUIRED_FIELDS = (USERNAME_FIELD, ""full_name"",)
}}}

Ignoring the fact that Django **knows** it's wrong to have it in there, and could easily just skip it or warn if it's not set, it doesn't make use of the hints available in system checks.

I'd like to suggest that a hint could be provided which says which field it's moaning about, something like (open to better wording):
{{{
HINT: Your username field is currently set to ""email"", you should remove ""email"" from your required fields definition.
}}}

It's a stupidly little thing, but having not had to make a custom user from scratch for a while, my eyes glazed over the **not** in ` must not be ` and I was confused for all of 2 minutes before actually reading it properly."	Cleanup/optimization	closed	Core (System checks)	3.0	Normal	fixed			Ready for checkin	1	0	0	0	1	0