could not load imported package and not generating file.

[devinyonas]

Hi, I got issue where i run build_runner but failed to generate any output. I mainly used it with stacked_cli, but failed to generating files.

[✓] Flutter (Channel stable, 3.32.0, on macOS 15.5 24F74 darwin-arm64, locale en-ID) [2.2s]
    • Flutter version 3.32.0 on channel stable at /Users/devin/fvm/versions/3.32.0
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision be698c48a6 (4 weeks ago), 2025-05-19 12:59:14 -0700
    • Engine revision 1881800949
    • Dart version 3.8.0
    • DevTools version 2.45.1

dart run build_runner build --delete-conflicting-outputs  
[WARNING] Could not load imported package "flag_builder" for definition "circle_flags:assetsToCache".
[WARNING] Could not load imported package "flag_builder" for definition "circle_flags:combineFlagFile".
[INFO] Generating build script completed, took 214ms
[INFO] Reading cached asset graph completed, took 692ms
[INFO] Checking for updates since last build completed, took 1.2s
[INFO] Running build completed, took 91ms
[INFO] Caching finalized dependency graph completed, took 290ms
[INFO] Succeeded after 396ms with 0 outputs (0 actions)

Let me know if you need more information

[davidmorgan]

Did it work before? What changed?

[devinyonas]

Did it work before? What changed?

Yes it work as usual previously. I think we upgrade the flutter version and bump the package version. Let me check with previous versions.

[jodinathan]

also with this problem.
I am upgrading Flutter to latest now to see if this stops

[jodinathan]

the messages are still there but the output was alright.

I guess cleaning everything made the build work, not the Flutter version.

[devinyonas]

You are right, in new clean project its work as expected. it generated the new testService

here is the log:

Running dart run build_runner build --delete-conflicting-outputs ...
  Generating the build script.

  Reading the asset graph.

  Checking for updates.

  Updating the asset graph.

  Building, incremental build.

  0s stacked_generator:stackedRouterGenerator on 19 inputs; lib/app/app.dart

  8s stacked_generator:stackedRouterGenerator on 19 inputs: 1 same; spent 7s analyzing, 1s resolving; lib/main.dart

  9s stacked_generator:stackedRouterGenerator on 19 inputs: 18 skipped, 1 same; spent 7s analyzing, 1s resolving
  0s stacked_generator:stackedLoggerGenerator on 38 inputs; lib/app/app.dart

  0s stacked_generator:stackedLoggerGenerator on 38 inputs: 37 skipped, 1 no-op
  0s stacked_generator:stackedLocatorGenerator on 76 inputs; lib/app/app.dart

  0s stacked_generator:stackedLocatorGenerator on 76 inputs: 75 skipped, 1 output
  0s stacked_generator:stackedFormGenerator on 152 inputs; lib/app/app.dart

  0s stacked_generator:stackedFormGenerator on 152 inputs: 149 skipped, 3 no-op
  0s stacked_generator:stackedDialogGenerator on 304 inputs; lib/app/app.dart

W stacked_generator:stackedRouterGenerator on lib/app/app.dart:
  Your current `analyzer` version may not fully support your current SDK version.
  
  Analyzer language version: 3.7.0
  SDK language version: 3.8.0
  
  Please update to the latest `analyzer` version (7.4.5) by running
  `flutter packages upgrade`.
  
  If you are not getting the latest version by running the above command, you
  can try adding a constraint like the following to your pubspec to start
  diagnosing why you can't get the latest version:
  
  dev_dependencies:
    analyzer: ^7.4.5
  

  0s stacked_generator:stackedDialogGenerator on 304 inputs: 301 skipped, 1 same, 2 no-op
  0s stacked_generator:stackedBottomsheetGenerator on 608 inputs; lib/app/app.dart

  0s stacked_generator:stackedBottomsheetGenerator on 608 inputs: 605 skipped, 1 same, 2 no-op
  0s mockito:mockBuilder on 320 inputs; test/golden/home_view_golden_test.bottomsheets.dart

  1s mockito:mockBuilder on 320 inputs: 1 skipped, 1 no-op; test/golden/home_view_golden_test.dialogs.bottomsheets.dart

  1s mockito:mockBuilder on 320 inputs: 315 skipped, 1 same, 4 no-op
  Running the post build.

  Writing the asset graph.

  Built with build_runner in 11s; wrote 5 outputs.

[devinyonas]

I guess cleaning everything made the build work, not the Flutter version.

@jodinathan what cleaning do you perform?

I tried flutter clean and remove pubspec.lock but still cannot generate the files.

here is the log in the project:

Running dart run build_runner build --delete-conflicting-outputs ...
[INFO] Generating build script...

[WARNING] Could not load imported package "flag_builder" for definition "circle_flags:assetsToCache".

[WARNING] Could not load imported package "flag_builder" for definition "circle_flags:combineFlagFile".

[INFO] Generating build script completed, took 220ms


[INFO] Precompiling build script......

[INFO] Precompiling build script... completed, took 3.8s


[INFO] Initializing inputs

[INFO] Building new asset graph...

[INFO] Building new asset graph completed, took 2.1s

[INFO] Checking for unexpected pre-existing outputs....
[INFO] Deleting 81 declared outputs which already existed on disk.

[INFO] Checking for unexpected pre-existing outputs. completed, took 0ms


[INFO] Running build...

[INFO] Generating SDK summary...

[INFO] 1.8s elapsed, 0/16 actions completed.

[INFO] 3.3s elapsed, 0/16 actions completed.

[INFO] Generating SDK summary completed, took 4.1s


[INFO] 5.2s elapsed, 32/142 actions completed.

[INFO] 6.2s elapsed, 71/154 actions completed.

[INFO] 7.4s elapsed, 80/157 actions completed.

[INFO] 8.5s elapsed, 96/162 actions completed.

[INFO] 9.6s elapsed, 160/207 actions completed.

[INFO] 20.9s elapsed, 243/265 actions completed.

[INFO] 33.0s elapsed, 270/286 actions completed.

[INFO] 34.1s elapsed, 339/360 actions completed.

[INFO] 35.3s elapsed, 379/396 actions completed.

[INFO] 36.3s elapsed, 413/432 actions completed.

[INFO] 37.4s elapsed, 449/468 actions completed.

[INFO] 39.0s elapsed, 487/503 actions completed.

[INFO] 40.0s elapsed, 531/547 actions completed.

[INFO] 41.1s elapsed, 587/602 actions completed.

[INFO] 42.2s elapsed, 629/644 actions completed.

[INFO] 43.3s elapsed, 639/654 actions completed.

[INFO] 44.3s elapsed, 667/683 actions completed.

[INFO] 45.4s elapsed, 799/813 actions completed.

[INFO] 46.4s elapsed, 1047/1047 actions completed.

[INFO] 47.4s elapsed, 1693/1709 actions completed.

[INFO] 48.5s elapsed, 2162/2162 actions completed.

[INFO] Running build completed, took 48.8s

[INFO] Caching finalized dependency graph...

[INFO] Caching finalized dependency graph completed, took 375ms


[INFO] Succeeded after 49.3s with 456 outputs (3120 actions)


Command complete. ExitCode: 0
Running dart format . -l 80 ...
Formatted lib/l10n/arb/app_localizations.dart

Formatted 938 files (1 changed) in 2.64 seconds.

Command complete. ExitCode: 0

its succeed but app.locator.dart file from stacked is not generated.

[antoniomtnez]

Any solution?

[davidmorgan]

@antoniomtnez we did not identify a specific issue, so it's hard to say if there is a solution :)

Are you using the same builder?

The logs on this issue are all from an old version of build_runner, the first thing I would suggest is to update packages as far as possible.

[devinyonas]

Hi @davidmorgan @antoniomtnez it seems previously the stacked_generator package is missing from my dev_dependencies. and I also update it to the latest version. Its working fine now. will close this thread

[xvrh]

@davidmorgan I think with the latest version of build_runner what was previously a warning becomes a crash.

https://github.com/cedvdb/flutter_circle_flags/issues/45 The package circle_flags declares an incorrect builder.

This used to only be a warning like this:

  Generating the build script.
W Could not load imported package "flag_builder" for definition "circle_flags:assetsToCache".
W Could not load imported package "flag_builder" for definition "circle_flags:combineFlagFile".

Now it is a crash:

E Error: Couldn't resolve the package 'flag_builder' in 'package:flag_builder/builders.dart'.
  .dart_tool/build/entrypoint/build.dart:6:8: Error: Not found: 'package:flag_builder/builders.dart'
  import 'package:flag_builder/builders.dart' as _i2;
         ^
  .dart_tool/build/entrypoint/build.dart:15:40: Error: Undefined name 'assetsToCache'.
      'circle_flags:assetsToCache': [_i2.assetsToCache],
                                         ^^^^^^^^^^^^^
  .dart_tool/build/entrypoint/build.dart:16:42: Error: Undefined name 'combineFlagFile'.
      'circle_flags:combineFlagFile': [_i2.combineFlagFile],
                                           ^^^^^^^^^^^^^^^
E Failed to compile build script. Check builder definitions and generated script .dart_tool/build/entrypoint/build.dart.

[davidmorgan]

Thanks @xvrh. That looks like a different issue, so opened

https://github.com/dart-lang/build/issues/4239

[antoniomtnez]

I solved that problem by installing this package: stacked_generator