Linker fails to link open method that was previously internal

Number:rdar://50619960 Date Originated:2019-05-09
Status:Open Resolved:
Product:Xcode Product Version:10.2.1
Classification: Reproducible:Yes
In the attached zip, I have a project that includes a framework. In the framework's class hierarchy, a subclass makes an internal 'initialize' method open. In the app, I subclass that class with an open 'initialize' method and try to build.

In Debug, it builds fine. In Release, the linker fails to find the method descriptor for that method and the build fails.

Steps to Reproduce:
1. Open the attached Project
2. Select the Release scheme
3. Build

Expected Results:
It builds without issue. Or at least, it builds with the exact same result in the Debug scheme.

Actual Results:
It fails to build with a linker error.

Xcode Version 10.2.1 (10E1001)

macOS 10.14.4 (18E226)


This just got marked as a dupe of rdar://48330571

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