flutter build apk ignores --target-platform if --debug is set

[thgoebel]

Report

rinf always compiles for x86_64 and x86_32 when --debug is passed. Flutter's --target-platform flag is ignoed.

Steps to Reproduce

1. flutter create testproject
2. cd testproject
3. Add rinf to it (details omitted)
4. flutter build apk --target-platform=android-arm64 --debug

Expected results

The resulting app-debug.apk only contains code for android-arm64.

Actual results

The resulting app-debug.apk contains code for android-arm, android-arm64, android-x86, android-x64.

When running without --debug, i.e. flutter build apk --target-platform=android-arm64 then the resulting app-release.apk correctly contains only code for android-arm64.

Why this is relevant

(Re)compiling Rust code for 4 target archs takes a loooong time (e.g. after a flutter clean). But I only need and only want to compile for one arch, because I am working on a physical test device. I expect --target-platform to work with --debug.

I see that by default one may want to include x86_64 and x86_32 for debug builds. But if I explicitly set --target-platform, I want this choice to be respected, and not have flutter and/or rinf trying to be clever and build for two additional platforms.

Context

I also filed a bug against this with Flutter: flutter/flutter#153359

Flutter implements this "default x86 behaviour" here: https://github.com/flutter/flutter/blob/6608936e6d430926eddc5759e2c4ca07dc873b03/packages/flutter_tools/gradle/src/main/groovy/flutter.groovy#L642

Nevertheless, this still needs to be tracked for rinf separately. Because rinf does the same thing as Flutter:

rinf/flutter_ffi_plugin/cargokit/gradle/plugin.gradle

Line 130 in 5f9b00c

// Same thing addFlutterDependencies does in flutter.gradle

. So both Flutter and rinf would need to implement logic to respect --target-platform.

System Information

$ rustc --version
rustc 1.82.0-nightly (91376f416 2024-08-12)

$ flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.24.0, on macOS 14.5 23F79 darwin-arm64, locale en-CH)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 15.4)
[✗] Chrome - develop for the web (Cannot find Chrome executable at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.
[✓] Android Studio (version 2024.1)
[✓] VS Code (version 1.92.0)
[✓] Connected device (3 available)
[✓] Network resources

! Doctor found issues in 1 category

[temeddix]

Thanks for reporting, I'll be investigating this issue as soon as I can. Meanwhile, we are open to PRs :)

[temeddix]

I think we need to communicate with cargokit, because Rinf is basically using Cargokit under the hood. /flutter_package/cargokit is a Git subtree directory pulled from Cargokit.