We're experiencing a severe main thread hang (29 seconds) in our CarPlay audio app when calling [CPListItem setImage:] on iOS 26.4. This issue affects 81% of our reported hang cases, and is concentrated on iOS 26.4. Environment iOS 26.4 CarPlay Audio app Images are downloaded via SDWebImage, resized to appropriate scale, then set via [CPListItem setImage:] on the main thread Problem When multiple list item images finish downloading around the same time, each setImage: call triggers expensive synchronous CoreUI operations on the main thread. The total accumulated time causes a 29-second freeze. The entire hang occurs inside Apple frameworks — no app code is on the hot path after calling setImage:. Call Stack (simplified) [CPListItem setImage:] └─ [CPImageSet initWithImage:treatmentBlock:] (57% + 21% + 18% = 96%) └─ [UIImageAsset imageWithTraitCollection:] └─ [UIImageAsset _withLock_imageWithConfiguration:] └─ [UIImageAsset _performLookUpRegisteredObjectForTraitCollection:] └─ [UITraitCollection _enume
Topic:
UI Frameworks
SubTopic:
UIKit
1
0
68