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
26693	RenameModel causes state.apps rendering leading to massive time increase in makemigrations	Simon Percivall	nobody	"Not 100% sure I have complete understanding of what happens, or why, but it seems a `RenameModel` migration leads to an evaluation of `state.apps`, which affects the time it takes for it and all following migration states to be calculated.

This is for a pretty big app, with lots of migrations. The time to run `makemigrations` for all apps goes from 1 seconds to 77 seconds with one `RenameModel` migration.

A test where `apps.state` was replaced by `temp_state = state.close(); apps = temp_state.apps` resolved the issue, but I'm not completely sure of the side effects of doing that. (Or even better if it were possible to check immediately if `'apps' in state.__dict__` and skip the rendering completely.)"	Cleanup/optimization	closed	Migrations	1.10	Normal	duplicate			Accepted	1	0	1	1	0	0