Xcode crashes when I try to run an app in the simulator

Number:rdar://38180319 Date Originated:06-Mar-2018 11:18 AM
Status:Duplicate of 34730177 Resolved:March 17 2018, 8:06 AM
Product:Developer Tools Product Version:Xcode 9.2 (9C40b) on macOS 10.13.3 (17D102)
Classification:Crash/Hang/Data Loss Reproducible:Always
Xcode is crashing whenever I try to build my iPad app in the iPad simulator. It has persisted across a computer restart. I don’t know what I might have done to get into this state. It was working fine when I put my computer to sleep last night, but the first build of the morning crashed Xcode. Same crash every time.

Steps to Reproduce:
1. Open a project in Xcode.
2. Try to run it on the iPad Air simulator.

Expected Results:
App runs.

Actual Results:
Simulator launches, but Xcode crashes due to an assertion failure because we are inserting a nil object into a dictionary.

Xcode 9.2 (9C40b) on macOS 10.13.3 (17D102)

Crash also uploaded to https://cl.ly/pxmS


Please note: Reports posted here will not necessarily be seen by Apple. All problems should be submitted at bugreport.apple.com before they are posted here. Please only post information for Radars that you have filed yourself, and please do not include Apple confidential information in your posts. Thank you!