Build.yaml no longer valid in latest build_runner

[talamaska]

Describe the bug
As noted in the docs I have added the following line in my build.yaml

targets:
  $default:
    sources:        // These lines with comments show how to declare the additional folders
      include:      // which contain the translations. In our case the i18n folder. Sadly
        - i18n/**   // if declare the include block we need to specify all our source folders
        - lib/**    // also.
    builders:
      rosetta:

In result I got some warnings and the generation is not working anymore

[WARNING] The package `my_app_name` does not include some required sources in any of its targets (see their build.yaml file).
  - $package$
[WARNING] Configuring `rosetta:rosetta` in target `sudoku_stats:sudoku_stats` but this is not a known Builder

Also tried setting
rosetta_generator in place of just rosetta

When I remove the builders, the second warning disappears.

To Reproduce
Steps to reproduce the behavior:

1. update the build_runner to 1.10.1
2. run flutter packages pub run build_runner build --delete-conflicting-outputs

Expected behavior
No warnings should be thrown

Desktop (please complete the following information):
[√] Flutter (Channel stable, 1.20.1, on Microsoft Windows [Version 10.0.18362.959], locale bg-BG)
[√] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
[√] Android Studio (version 4.0)
[√] VS Code, 64-bit edition (version 1.47.3)
[√] Connected device (1 available)

Flutter 1.20.1 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 2ae34518b8 (35 hours ago) • 2020-08-05 19:53:19 -0700
Engine • revision c8e3b94853
Tools • Dart 2.9.0

[RenatoKiss]

Hi talamaska!

Can you show a minimal repo or part of your code for help?
I tried to reproduce the issue, but I couldn't.

You should place both rosetta and rosetta_generator into dependencies. Maybe that was your problem.

[talamaska]

No, in the custom build.yaml where we point the folders to parse. We need to add an additional line in the end.
- $package$

[talamaska]

You should change it in the example and in the docs. This change comes from build_runner with newer releases around flutter 1.20 release.

[talamaska]

dart-lang/build#2781 (comment)

[RenatoKiss]

Changes merged into stable