Interface builder should allow crashing for invalid classes

Originator:keithbsmiley
Number:rdar://33506080 Date Originated:24-Jul-2017 22:59
Status:Open Resolved:
Product:Developer Tools Product Version:Xcode 9 beta 4
Classification:Other Bug Reproducible:Always
 
Summary:
Currently if you define a custom class for a view in IB, if the class doesn't exist in runtime, a non-fatal exception is logged, but the app continues working, often without the correct UX since the custom class behavior isn't happening.

Steps to Reproduce:
1. Create a new project
2. Add a label on screen
3. Change the label's class to Foo
4. Run the app

Expected Results:
The app crashes at runtime because the class `Foo` doesn't exist

Actual Results:
An error is logged, but the app continues to run.

Version:
Xcode 9 beta 4

Notes:
- I think a opt-in error for this would also be acceptable, but either way this is a runtime error that shouldn't be avoidable.
- Run the attached project for an example

Comments


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