[Impeller] [Windows] --no-enable-impeller does not disable Impeller in release mode #190910

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1. puneetkukreja98

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   in triagePresently being triaged by the triage teamPresently being triaged by the triage team

   on Aug 11, 2026
2. puneetkukreja98 commented on Aug 11, 2026

   

   puneetkukreja98

   on Aug 11, 2026

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   @Razorex001 Thanks for reporting the issue. I was able to reproduce it on latest master. When running in release mode with --no-enable-impeller, the logs show Using the Impeller rendering backend... whereas this doesn't happen in profile and debug mode.

   Console logs:

   PS C:\Google\win_impeller_master_app> flutter run -d windows --release --no-enable-impeller
   Launching lib\main.dart on Windows in release mode...
   Building Windows application...                                    34.4s
   √ Built build\windows\x64\runner\Release\win_impeller_master_app.exe
   
   Flutter run key commands.
   h List all available interactive commands.
   c Clear the screen
   q Quit (terminate the application on the device).
   
   [IMPORTANT:flutter/shell/platform/embedder/embedder_surface_gl_impeller.cc(127)] Using the Impeller rendering backend (OpenGLESSDF).
   
   Application finished.
   PS C:\Google\win_impeller_master_app> flutter run -d windows --profile --no-enable-impeller
   Launching lib\main.dart on Windows in profile mode...
   Building Windows application...                                    14.3s
   √ Built build\windows\x64\runner\Profile\win_impeller_master_app.exe
   
   Flutter run key commands.
   h List all available interactive commands.
   c Clear the screen
   q Quit (terminate the application on the device).
   
   A Dart VM Service on Windows is available at: http://127.0.0.1:61089/nP6kCVuOiTE=/
   The Flutter DevTools debugger and profiler on Windows is available at:
   http://127.0.0.1:61089/nP6kCVuOiTE=/devtools/?uri=ws://127.0.0.1:61089/nP6kCVuOiTE=/ws

   Flutter doctor -v:

   [√] Flutter (Channel master, 3.47.0-1.0.pre-505, on Microsoft Windows [Version 10.0.26200.8875], locale en-IN) [3.2s]
       • Flutter version 3.47.0-1.0.pre-505 on channel master at C:\Developer\flutter
       • Upstream repository https://github.com/flutter/flutter.git
       • Framework revision f20f4b26de (3 hours ago), 2026-08-11 10:01:39 +0000
       • Engine revision f20f4b26de
       • Dart version 3.14.0 (build 3.14.0-114.0.dev)
       • DevTools version 2.61.0-dev.0
       • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android,
         enable-ios, cli-animations, enable-native-assets, enable-record-use, enable-swift-package-manager,
         omit-legacy-version-file, enable-windowing, enable-lldb-debugging, enable-uiscene-migration, enable-riscv64
   
   [√] Windows Version (Windows 11 or higher, 25H2, 2009) [2.4s]
   
   [√] Android toolchain - develop for Android devices (Android SDK version 37.0.0) [3.5s]
       • Android SDK at C:\Users\Puneet\AppData\Local\Android\sdk
       • Emulator version 36.6.11.0 (build_id 15507667) (CL:N/A)
       • Platform android-37.1, build-tools 37.0.0
       • Java binary at: C:\Program Files\Android\Android Studio1\jbr\bin\java
         This is the JDK bundled with the latest Android Studio installation on this machine.
         To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
       • Java version OpenJDK Runtime Environment (build 21.0.10+-14961533-b1163.108)
       • All Android licenses accepted.
   
   [√] Chrome - develop for the web [104ms]
       • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe
   
   [√] Visual Studio - develop Windows apps (Visual Studio Community 2026 18.3.2) [102ms]
       • Visual Studio at C:\Program Files\Microsoft Visual Studio\18\Community
       • Visual Studio Community 2026 version 18.3.11520.95
       • Windows 10 SDK version 10.0.26100.0
   
   [√] Connected device (3 available) [307ms]
       • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.26200.8875]
       • Chrome (web)      • chrome  • web-javascript • Google Chrome 151.0.7922.77
       • Edge (web)        • edge    • web-javascript • Microsoft Edge 151.0.4129.72
   
   [√] Network resources [987ms]
       • All expected network resources are available.
   
   • No issues found!
3. puneetkukreja98 commented on Aug 11, 2026

   

   puneetkukreja98

   on Aug 11, 2026

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   Related issue: #187737
4. puneetkukreja98

   added

   engineflutter/engine related. See also e: labels.flutter/engine related. See also e: labels.

   platform-windowsBuilding on or for Windows specificallyBuilding on or for Windows specifically

   e: impellerImpeller rendering backend issues and features requestsImpeller rendering backend issues and features requests

   team-engineOwned by Engine teamOwned by Engine team

   fyi-windowsFor the attention of the Windows platform teamFor the attention of the Windows platform team

   and removed

   in triagePresently being triaged by the triage teamPresently being triaged by the triage team

   on Aug 11, 2026
5. loic-sharma

   added

   P0Critical issues such as a build break or regressionCritical issues such as a build break or regression

   P1High-priority issues at the top of the work listHigh-priority issues at the top of the work list

   and removed

   P0Critical issues such as a build break or regressionCritical issues such as a build break or regression

   on Aug 12, 2026
6. loic-sharma commented on Aug 12, 2026

   

   loic-sharma

   on Aug 12, 2026

   Last edited by loic-sharma

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   @Razorex001 Thanks for filing this bug! Are you able to opt-out of Impeller in release mode if you add the following content to your windows\runner\main.cpp file?

   project.set_impeller_switch(flutter::ImpellerSwitch::Disabled);

   @gaaclarke I marked this as a P1 as this might prevent people from opt-ing out of Impeller on stable.
7. Razorex001 commented on Aug 12, 2026

   

   Razorex001

   on Aug 12, 2026

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   @Razorex001 Thanks for filing this bug! Are you able to opt-out of Impeller in release mode if you add the following content to your windows\runner\main.cpp file?

   project.set_impeller_switch(flutter::ImpellerSwitch::Disabled);
   @gaaclarke I marked this as a P1 as this might prevent people from opt-ing out of Impeller on stable.

   I just tested it. running app with:

   flutter run -d windows --release --no-enable-impeller
   

   with ImpellerSwitch disabled in main.cpp the app used Skia so I was able to opt-out.

   Also running the app with:

   flutter run -d windows --release
   

   results in Skia being used. This is still not ideal because one would expect that when the flag is not used, it uses Impeller by default, but at the very least it is possible to opt out with that line, which I guess is better than nothing.

   👍React with 👍1Reacted by Loïc Sharma
8. gaaclarke commented on Aug 12, 2026

   

   gaaclarke

   on Aug 12, 2026

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   This is still not ideal because one would expect that when the flag is not used, it uses Impeller by default

   That's the intended behavior. If you supply no command-line flag you will get whatever the project settings are or impeller if you never set them.

   There is a case where the project flag and the command-line flag do no agree, we need to give preference to one of them. The way it should work is that command-line flags get the preference.
9. gaaclarke commented on Aug 12, 2026

   

   gaaclarke

   on Aug 12, 2026

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   This is works-as-intended. The flags that control the graphics backend intentionally don't work in release builds. You are supposed to set them with internal project flags. We could be a better partner though and warn users when that flag is ignored. I'll file a followup issue for that.

   👍React with 👍1Reacted by Razorex001
10. gaaclarke

    closed this as completedon Aug 12, 2026
11. gaaclarke commented on Aug 12, 2026

    

    gaaclarke

    on Aug 12, 2026

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    filed: #191027
12. github-actions commented on Aug 26, 2026

    

    github-actionsBot

    on Aug 26, 2026 – with GitHub Actions

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    This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.
13. github-actions

    locked as resolved and limited conversation to collaborators on Aug 26, 2026