scenario_app build rules doesn't recompile when files are edited

[gaaclarke]

Steps to reproduce:

1. Type garbage into the file at flutter/testing/scenario_app/lib/src/scenarios.dart
2. delete out/ios_debug_sim_unopt/scenario_app/Scenarios/App.framework
3. compile with autoninja -C out/ios_debug_sim_unopt && autoninja -C out/host_debug_unopt/
4. Notice that there was no compilation error
5. Notice that out/ios_debug_sim_unopt/scenario_app/Scenarios/App.framework has been regenerated somehow despite the error

cc @dnfield

[dnfield]

This is jit mode. App.framework is a stub in that case. You should get an error during kernel complication though

[gaaclarke]

Ahh okay, the problem is made worse because the App.framework is used in UI tests which makes it hard to debug problems in the underlying process.

[gaaclarke]

If you delete the App.framework from the source directory and rebuild it doesn't seem to perform the copy either. I don't know if I should file another issue for that.

example:

$ find flutter/ -name "App.framework" -exec rm {} \;
$ autoninja -C out/ios_debug_sim_unopt scenario_app
ninja: Entering directory `out/ios_debug_sim_unopt'
[4/4] STAMP obj/flutter/testing/scenario_app/scenario_app.stamp
$ find flutter/ -name "App.framework"
$ 

[dnfield]

Oh!

It's all in the out/ios_debug_sim_unopt/scenario_app now intead of in the source tree.

[dnfield]

e.g.

find out/ios_debug_sim_unopt -name App.framework                            
out/ios_debug_sim_unopt/scenario_app/Scenarios/App.framework

I think this is WAI...

[gaaclarke]

@dnfield What about these copy rules: https://github.com/flutter/engine/blob/b288e8a84c89a098e430f00a5ecfd019396603f7/testing/scenario_app/ios/BUILD.gn#L30

It looks like the xcodeproj is referencing those too, not the ones in the out directory

[dnfield]

The whole xcodeproj is copied. The reference in it is relative. It will only work when opened from the out dir.

[dnfield]

https://github.com/flutter/engine/blob/b288e8a84c89a098e430f00a5ecfd019396603f7/testing/scenario_app/ios/BUILD.gn#L40-L56

[gaaclarke]

I still don't quite know how this is supposed to work. Let's sync up monday when you are back in the office. I'm missing something, thanks for you help dan.

[gaaclarke]

Ahh, okay I get it at least. I had a residual App.framework from the way things previously worked, and was looking for it to regenerate stuff there. This is WAI, but I'm still having troubles getting a new test to run. At least I understand how it's supposed to work now.

[gaaclarke]

shoot, got so caught up with the other issue I mentioned I forgot that it was off topic from the original issue of not having compilation errors show up.