Description
Steps to reproduce
Description:
In the release build of my Flutter Web application (using the CanvasKit renderer), I’m encountering the following runtime error in the browser console:
VM134 main.dart.js:3481 Uncaught Error: BindingError: Expected null or instance of Picture, got an instance of Picture
at Q (canvaskit.js:101:251)
at Xb (canvaskit.js:108:38)
at cc.$b [as toWireType] (canvaskit.js:109:408)
at Tb._drawPicture (canvaskit.js:116:8)
at a.Canvas.drawPicture (canvaskit.js:49:299)
at Qt.Mq (main.dart.js:32807:3)
at mX.eJ (main.dart.js:32455:11)
at Qt.mN (main.dart.js:32723:14)
at Qt.ud (main.dart.js:32772:6)
at Qt.Mo (main.dart.js:32774:12)
Important Context:
This issue only occurs in the release build (flutter build web --release), not in debug or profile mode.
The object is definitely a ui.Picture, created using ui.PictureRecorder.
The error suggests a type mismatch between Dart and the CanvasKit WASM layer, even though the object is correct on the Dart side.
Steps to Reproduce:
Create a ui.Picture using PictureRecorder.
Store or reuse the Picture in a widget or painter.
In release mode, try to draw it using canvas.drawPicture(...).
Expected Behavior:
The picture should render correctly without any runtime errors.
Actual Behavior:
In the release build, a BindingError is thrown, claiming the object is not a valid Picture, although it was created properly.
Flutter Version:
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.24.5, on macOS 15.1.1 24B91 darwin-arm64, locale en-GB)
[!] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
✗ cmdline-tools component is missing
Run `path/to/sdkmanager --install "cmdline-tools;latest"`
See https://developer.android.com/studio/command-line for more details.
✗ Android license status unknown.
Run `flutter doctor --android-licenses` to accept the SDK licenses.
See https://flutter.dev/to/macos-android-setup for more details.
[✗] Xcode - develop for iOS and macOS
✗ Xcode installation is incomplete; a full installation is necessary for iOS and macOS development.
Download at: https://developer.apple.com/xcode/
Or install Xcode via the App Store.
Once installed, run:
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
sudo xcodebuild -runFirstLaunch
✗ CocoaPods not installed.
CocoaPods is a package manager for iOS or macOS platform code.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/to/platform-plugins
For installation instructions, see https://guides.cocoapods.org/using/getting-started.html#installation
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] Connected device (2 available)
[✓] Network resources
Target Platform:
Flutter Web (CanvasKit renderer) — Release Mode
Browser:
(Please include browser name and version, e.g., Chrome 124, Edge 123, etc.)
Additional Notes:
This might be related to how objects are compiled/minified or optimized in release mode.
Possibly an issue with how CanvasKit/WASM bindings verify object instances.
Please advise if there's a workaround, or if further reproduction steps or a minimal example is required.
Expected results
VM134 main.dart.js:3481 Uncaught Error: BindingError: Expected null or instance of Picture, got an instance of Picture
at Q (canvaskit.js:101:251)
at Xb (canvaskit.js:108:38)
at cc.$b [as toWireType] (canvaskit.js:109:408)
at Tb._drawPicture (canvaskit.js:116:8)
at a.Canvas.drawPicture (canvaskit.js:49:299)
at Qt.Mq (main.dart.js:32807:3)
at mX.eJ (main.dart.js:32455:11)
at Qt.mN (main.dart.js:32723:14)
at Qt.ud (main.dart.js:32772:6)
at Qt.Mo (main.dart.js:32774:12)
Actual results
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Code sample
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