Xcode 9 beta 4 crashes when adding a project to an open workspace/project

Number:rdar://33565820 Date Originated:July 27 2017
Status:Duplicate Resolved:No
Product:Xcode Product Version:Xcode 9.0 beta 4 (9M189t)
Classification:Crash Reproducible:Yes
When a project is added to an existing workspace or project, Xcode crashes.

Steps to Reproduce:
- Create a new project A in Xcode, close it.
- Create a new project B in Xcode
- Drag projectA.xcodeproj into the navigation pane of project B
- (alternatively) right click the navigation pane, "Add files…", and select projectA.xcodeproj

Expected Results:
Project A is added to Project B's hierarchy

Observed Results:
Xcode crashes immediately. On re-launch, Project B is unchanged (does not contain project A in the file hierarchy)



Open an existing project and select "File > Save as Workspace..". The adding more projects to this workspace does not crash Xcode.

Using Version 9.0 beta 5 (9M202q).

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