Duplication dart class in Mac OS product app

[loongliu]

setup the engine development environment according this

I changed some code both embedder.c and flutter/lib/ui/*.dart in flutter engine, add some instance variable to dart class.

build and copy the FlutterEmbedder.framework to desired location: flutter_engine_framework/macos/FlutterEmbedder.framework (in the original build pipeline, FlutterEmbedder.framework is downloaded from network)

Then change some code in flutter/flutter, this code depends on the dart code change in engine.

Build the macos example project with Debug configuration. Run the result Example Embedder.app.

I found both my dart code changes in engine and flutter/flutter works (two logs both printed). But the code in flutter/flutter does not find the instance variable previously added to flutter/lib/ui/*.dart.
And Application crashed.

After some debug, I found flutter/lib/ui/*.dart class is duplicated in product app.

There are two files in app folder (Right click Example Embedder.app and click Show Package Contents):

1. Contents/Resources/flutter_assets/vm_snapshot_data
2. Contents/Frameworks/FlutterEmbedderMac.framework/Versions/A/Frameworks/FlutterEmbedder.framework/Versions/Current/FlutterEmbedder.

file 1: app build result by flutter build bundle
file 2: engine build result by ninja -C

Check the file contents by Mac command line strings /path/to/file1or2 > output1or2.txt

Search for flutter/lib/ui/ in these generated output.txt, you can find flutter/lib/ui/*.dart class in both files.

Is anything wrong with my build settings?

[stuartmorgan]

Did you follow the instructions here?

(Issue #160 is about making what you are trying to do easier to set up.)

[stuartmorgan]

I'm a little confused as to why you've inlined build_flutter_assets into Xcode rather than modifying the script in place, but I'm not seeing any obvious issues with what you've posted. Other than deleting .../flutter_engine_framework/macos/FlutterEmbedder.framework and .../flutter_app/build just to make sure nothing is stale, I don't have any immediate suggestions. And maybe delete flutter/bin/cache as I think I saw a case where the previously-downloaded cache of sky_engine was being used instead of the new engine version (but I can't find where I encountered that, so may be misremembering).

If you provide the hashes for your Flutter tree and Flutter engine tree I can test a local engine override with the same versions to see if I can reproduce your issue with that version.

[krisgiesing]

Did you pass --local-engine-src-path when running flutter build bundle? My understanding is that that's required when using a local engine build. I can see that might cause you to wind up with an extra copy in the built bundle.

[stuartmorgan]

The script in the first screenshot is (a slightly modified version of) the script I linked to above that passes that flag, showing the relevant lines uncommented.

[krisgiesing]

You're right, apologies for missing that.

[loongliu]

I'm a little confused as to why you've inlined build_flutter_assets into Xcode rather than modifying the script in place.
If you provide the hashes for your Flutter tree and Flutter engine tree I can test a local engine override with the same versions to see if I can reproduce your issue with that version.

Inline script is easier to modify in Xcode environment, since I don't need Linux built product.

flutter commit SHA : 0f10d3f992410a712af77a1d82ebe32aeeb4ef1c
engine commit SHA: 0e9ad4341695b8825ba90c60ce980f363ceb6c53

Notice that I do commit some changes locally base on posted SHA. so current SHA locally is not same as posted. However my commit should not change the build pipeline

[loongliu]

After remove flutter/bin/cache, compile error fixed and app works fine.

So no block for my work. Close this issue for this moment.

When more time is available, I will do more check about whether dart class is duplicated.