Crash: Unexpectedly found nil while unwrapping an Optional value

[jcmosc]

This contains a test case that reproduces a crash when nesting multi root variadic views:
#791

[augmentcode]

🤖 Augment PR Summary

Summary: Adds a regression test reproducing a fatal optional-unwrapping crash when nesting variadic view roots.

Changes:

• Introduces passthrough unary and multi variadic view roots for testing
• Adds two Darwin-only tests that build nested _VariadicView.Tree hierarchies with Color.red/Color.blue
• Drives rendering via ViewGraph and requests a .displayList output
• Validates the produced display list structure using a regex match on displayList.description

Technical Notes: Tests run only under #if canImport(Darwin) and exercise the dynamic display-list path that previously hit the nil unwrap in ForEach internals.

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[augmentcode]

Review completed. 1 suggestions posted.

Comment augment review to trigger a new review at any time.

[augmentcode]

Since this PR adds only the repro test, if the underlying crash is still present this will abort the whole test run (fatal error) rather than reporting a normal test failure; is this intended to land only together with the fix or be marked as an expected failure until then?

Severity: medium

Other Locations

• Tests/OpenSwiftUICoreTests/View/VariadicViewTests.swift:26

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