Flutter Failed to build appbundle when using DeferredComponent

Question

I'm using DeferredComponent in my Flutter project. The app run successfully in debug and release mode. However, when I try to make an appbundle, the Deferred Components validation fails with the following error.

ERROR LOG

=================================================================================
                     Deferred components prebuild validation
=================================================================================
Modified android files:
  - salt_coding_challenge\build\android_deferred_components_setup_files\app\src\main\res\values\strings.xml

The above files have been placed into `build/android_deferred_components_setup_files`,
a temporary directory. The files should be reviewed and moved into the project's
`android` directory.
---------------------------------------------------------------------------------

Setup verification can be skipped by passing the `--no-validate-deferred-components`
flag, however, doing so may put your app at risk of not functioning even if the
build is successful.
=================================================================================
Setup for deferred components incomplete. See recommended actions.
PS C:\Data\StudioProjects\salt_coding_challenge> flutter build appbundle -v
[  +18 ms] executing: [C:\src\flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[  +62 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[   +1 ms] 9944297138845a94256f1cf37beb88ff9a8e811a
[        ] executing: [C:\src\flutter/] git tag --points-at 9944297138845a94256f1cf37beb88ff9a8e811a
[  +72 ms] Exit code 0 from: git tag --points-at 9944297138845a94256f1cf37beb88ff9a8e811a
[        ] 3.7.3
[  +16 ms] executing: [C:\src\flutter/] git rev-parse --abbrev-ref --symbolic @{upstream}
[  +44 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{upstream}
[        ] origin/stable
[        ] executing: [C:\src\flutter/] git ls-remote --get-url origin
[  +52 ms] Exit code 0 from: git ls-remote --get-url origin
[        ] https://github.com/flutter/flutter.git
[  +63 ms] executing: [C:\src\flutter/] git rev-parse --abbrev-ref HEAD
[  +49 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] stable
[  +46 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +4 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +35 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
[        ] Artifact Instance of 'GradleWrapper' is not required, skipping update.
[   +1 ms] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[        ] Artifact Instance of 'FlutterSdk' is not required, skipping update.
[        ] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'PubDependencies' is not required, skipping update.
[  +96 ms] Skipping pub get: version match.
[  +87 ms] Found plugin webview_flutter at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter-3.0.4\
[   +4 ms] Found plugin webview_flutter_android at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter_android-2.10.4\
[   +2 ms] Found plugin webview_flutter_wkwebview at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter_wkwebview-2.9.5\
[  +61 ms] Found plugin webview_flutter at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter-3.0.4\
[   +1 ms] Found plugin webview_flutter_android at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter_android-2.10.4\
[   +1 ms] Found plugin webview_flutter_wkwebview at C:\Users\Rajabi\AppData\Local\Pub\Cache\hosted\pub.dev\webview_flutter_wkwebview-2.9.5\
[   +7 ms] Generating C:\Data\StudioProjects\salt_coding_challenge\android\app\src\main\java\io\flutter\plugins\GeneratedPluginRegistrant.java
[  +91 ms] =================================================================================
[   +1 ms]                      Deferred components prebuild validation
[        ] =================================================================================
[        ] Modified android files:
[        ]   - salt_coding_challenge\build\android_deferred_components_setup_files\app\src\main\res\values\strings.xml
[        ] The above files have been placed into `build/android_deferred_components_setup_files`,
           a temporary directory. The files should be reviewed and moved into the project's
           `android` directory.
[        ] ---------------------------------------------------------------------------------

[        ] Setup verification can be skipped by passing the `--no-validate-deferred-components`
           flag, however, doing so may put your app at risk of not functioning even if the
           build is successful.
           =================================================================================
[   +8 ms] "flutter appbundle" took 507ms.
[   +3 ms] Setup for deferred components incomplete. See recommended actions.
[   +2 ms]
           #0      throwToolExit (package:flutter_tools/src/base/common.dart:10:3)
           #1      DeferredComponentsValidator.attemptToolExit (package:flutter_tools/src/android/deferred_components_validator.dart:220:7)
           #2      DeferredComponentsValidator.handleResults (package:flutter_tools/src/android/deferred_components_validator.dart:102:5)
           #3      BuildAppBundleCommand.runCommand (package:flutter_tools/src/commands/build_appbundle.dart:132:17)
           <asynchronous suspension>
           #4      FlutterCommand.run.<anonymous closure> (package:flutter_tools/src/runner/flutter_command.dart:1257:27)
           <asynchronous suspension>
           #5      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #6      CommandRunner.runCommand (package:args/command_runner.dart:209:13)
           <asynchronous suspension>
           #7      FlutterCommandRunner.runCommand.<anonymous closure> (package:flutter_tools/src/runner/flutter_command_runner.dart:283:9)
           <asynchronous suspension>
           #8      AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #9      FlutterCommandRunner.runCommand (package:flutter_tools/src/runner/flutter_command_runner.dart:229:5)
           <asynchronous suspension>
           #10     run.<anonymous closure>.<anonymous closure> (package:flutter_tools/runner.dart:64:9)
           <asynchronous suspension>
           #11     AppContext.run.<anonymous closure> (package:flutter_tools/src/base/context.dart:150:19)
           <asynchronous suspension>
           #12     main (package:flutter_tools/executable.dart:91:3)
           <asynchronous suspension>


[ +264 ms] ensureAnalyticsSent: 263ms
[        ] Running 0 shutdown hooks
[        ] Shutdown hooks complete
[        ] exiting with code 1

What's causing this error? And how to prevent it?

Modified android files:
  - salt_coding_challenge\build\android_deferred_components_setup_files\app\src\main\res\values\strings.xml

The above files have been placed into `build/android_deferred_components_setup_files`,
a temporary directory. The files should be reviewed and moved into the project's
`android` directory

Am I missing something when setting up my deferred component?

Answer 1

I finally found the answer. Basically, this error

Modified android files:
  - salt_coding_challenge\build\android_deferred_components_setup_files\app\src\main\res\values\strings.xml

The above files have been placed into `build/android_deferred_components_setup_files`,
a temporary directory. The files should be reviewed and moved into the project's
`android` directory

indicates there is an error within the moved files. In my case the moved file is string.xml. In my case, I called the string resources in the AndroidManifest.xml. I called @string/defComponent meanwhile the resources named defComponentName in strings.xml.