[SR-13068] Ambiguous expression instead of specific error

[swift-ci]

Previous ID	SR-13068
Radar	None
Original Reporter	stevex (JIRA User)
Type	Bug

Environment

Xcode 12.0 beta (12A6159) on Catalina.

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, DiagnosticsQoI, TypeChecker
Assignee	None
Priority	Medium

md5: 4cde12bc42c71a8af4bb02222eddbcd5

Issue Description:

This code gives "Type of expression is ambiguous without more context" on line 11 (the ZStack) when the actual error is type conversion on line 17.

/Users/stevex/Desktop/Demo/Demo/ContentView.swift:11:9: error: type of expression is ambiguous without more context
        ZStack {

import SwiftUI

class BoardMetrics: ObservableObject {
    @Published var cellSize = 30
}

struct CellView: View {
    @EnvironmentObject var boardMetrics: BoardMetrics

    var body: some View {
        ZStack {
            Rectangle()
                .border(Color.gray)
            
            Text("1")
                .border(Color.clear)
                .font(.system(size: Double(14 * boardMetrics.cellSize * 0.1)))
        }
    }
}