[SR-13361] if #available(iOS 14, *) Xcode 12 beta 4 crashed on iOS 13 device

[swift-ci]

Previous ID	SR-13361
Radar	rdar://problem/67361244
Original Reporter	Trahambb (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug
Assignee	@beccadax
Priority	Medium

md5: 6b8e7a5186e17177ccbd1f5290a2dd29

Issue Description:

When i try to use if #available(iOS 14, *) in Xcode 12 beta 4 to separate code for iOS 14 and lower i got a crash when building on iOS 13 device:

Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)

Example:

struct ContentView: View {
    var body: some View {
        if #available(iOS 14.0, *) {
            List {
                Text("iOS 14")
            }
            .listStyle(InsetGroupedListStyle())
        } else {
            List {
                Text("iOS 13")
            }
            .listStyle(GroupedListStyle())
            .environment(\.horizontalSizeClass, .regular)
        }
    }
}

SO original error

[typesanitizer]

@swift-ci create

[beccadax]

Trahambb (JIRA User) Thanks for reporting this. We made a change last month that should address this bug; I believe it shipped in beta 5. Can you see if this bug still occurs with the current Xcode beta?

[beccadax]

(Changing status to "Resolved" in anticipation of the reporter confirming that it has been fixed. Robar, if you can't reproduce this in beta 5 or later, please close this issue. If not, please reopen it.)