[SR-11776] Cyclic Metadata Dependency in Swift 5

[swift-ci]

Previous ID	SR-11776
Radar	rdar://problem/57176799
Original Reporter	ermik (JIRA User)
Type	Bug

Attachment: Download

Environment

Catalina 10.15.1

Xcode Version 11.2.1 (11B500)

Apple Swift version 5.1.2 (swiftlang-1100.0.278 clang-1100.0.33.9)

lldb-1100.0.30.6

Additional Detail from JIRA

Votes	0
Component/s	LLDB for Swift
Labels	Bug, Crash
Assignee	None
Priority	Medium

md5: 85111c25b68a2b55c03852724d967470

Issue Description:

Attached project builds successfully but results in EXC_BAD_ACCESS crash at class initializer callsite (RootBuilder.swift#46, marked). Running po ClassName.self ahead of crash produces the following output:

(lldb) po RootRouter.self
error: Execution was interrupted, reason: EXC_BAD_ACCESS (code=1, address=0x0).
The process has been returned to the state before expression evaluation.

(lldb) po RootRouter.self
SingletonMetadataCache(0x600003fdd5e0): cyclic metadata dependency detected, aborting
error: Execution was interrupted, reason: signal SIGABRT.
The process has been returned to the state before expression evaluation.

[beccadax]

@swift-ci create

[swift-ci]

Comment by Ermolay Romanov (JIRA)

brentdax (JIRA User) I see that there is some triage here, but what would you say the status of this is?

Thanks!