ci: build and test on Xcode 27 / Swift 6.4

.github/workflows/ci.yml

@@ -22,16 +22,17 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  # Pin the image (macos-15) and a GM Xcode by path. `macos-latest` +
-  # setup-xcode's `latest-stable` rolled onto a 26.6 Release Candidate whose
-  # XCTest runtime deadlocked the tests; a GM path fails loudly if the image
-  # drops it (bump then — never an RC).
-  DEVELOPER_DIR: /Applications/Xcode_26.3.app/Contents/Developer
+  # Pin the image (xcode-27, GitHub's image for the Xcode 27 line) and Xcode by
+  # path. `macos-latest` + setup-xcode's `latest-stable` rolled onto a 26.6
+  # Release Candidate whose XCTest runtime deadlocked the tests; a versioned path
+  # fails loudly if the image drops it (bump then). `Xcode_27.0.app` is the
+  # image's alias for the line, so it carries over when the image reaches the GM.
+  DEVELOPER_DIR: /Applications/Xcode_27.0.app/Contents/Developer
 
 jobs:
   build-and-unit:
     name: Build + unit tests
-    runs-on: macos-15
+    runs-on: xcode-27
     steps:
       - uses: actions/checkout@v5
 
@@ -92,7 +93,7 @@ jobs:
 
   ui-tests:
     name: UI tests
-    runs-on: macos-15
+    runs-on: xcode-27
     # Slow gate: run once a PR is ready for review (and on pushes to main), not on
     # draft pushes. A skipped required check still reports success, so drafts stay
     # mergeable-clean.

Pinwheel/Sources/Pinwheel/Capture/PinDisplayList.swift

@@ -190,8 +190,8 @@ enum PinDisplayList {
     // payload without descending into child display lists.
     private static func clipCornerRadius(_ payload: Any, _ depth: Int = 0) -> CGFloat? {
         if depth > 8 { return nil }
-        if String(describing: type(of: payload)).contains("FixedRoundedRect"), let size = child(payload, "cornerSize") as? CGSize {
-            return size.width
+        if String(describing: type(of: payload)).contains("FixedRoundedRect"), let radius = fixedRoundedRectRadius(payload) {
+            return radius
         }
         for field in Mirror(reflecting: payload).children where !isDisplayList(field.value) {
             if let radius = clipCornerRadius(field.value, depth + 1) { return radius }
@@ -307,11 +307,20 @@ enum PinDisplayList {
     // SwiftUI Path.storage is an enum; `.roundedRect(FixedRoundedRect)` exposes the exact corner size.
     private static func roundedRectRadius(_ path: Any?) -> CGFloat? {
         guard let path, let storage = child(path, "storage"), let (kind, value) = enumCase(storage) else { return nil }
-        if kind == "roundedRect", let size = child(value, "cornerSize") as? CGSize { return size.width }
+        if kind == "roundedRect" { return fixedRoundedRectRadius(value) }
         if kind == "rect" { return 0 }
         return nil
     }
 
+    // FixedRoundedRect carried `cornerSize: CGSize` through iOS 26 and carries `radii: Radii` from iOS 27,
+    // so read whichever this OS supplies. An `.uneven` radii has no single corner to report, and answering
+    // nil sends the shape down the rasterizing path rather than inventing a radius for it.
+    private static func fixedRoundedRectRadius(_ value: Any) -> CGFloat? {
+        if let size = child(value, "cornerSize") as? CGSize { return size.width }
+        guard let radii = child(value, "radii"), let (kind, corners) = enumCase(radii), kind == "uniform" else { return nil }
+        return corners as? CGFloat
+    }
+
     private static func nestedLists(in value: Any) -> [Any] {
         var found: [Any] = []
         for level1 in Mirror(reflecting: value).children {

Pinwheel/Sources/Pinwheel/Extensions/UIFontExtensions.swift

@@ -1,6 +1,6 @@
 import UIKit
 
-extension UIFont {
+nonisolated extension UIFont {
     public class func rounded(ofSize size: CGFloat, weight: UIFont.Weight) -> UIFont {
         let systemFont = UIFont.systemFont(ofSize: size, weight: weight)
         let font: UIFont
@@ -24,7 +24,7 @@ extension UIFont {
     }
 }
 
-extension UIFont.Weight {
+nonisolated extension UIFont.Weight {
     public var symbolWeight: UIImage.SymbolWeight {
         switch self {
         case .ultraLight: