Flutter gen-l10n untranslated messages warning false positive

[Sominemo]

Steps to Reproduce

1. flutter create .
2. create app_en.arb in lib/l10n, for example:

{
    "helloWorld": "Hello World",
    "@helloWorld": {
        "description": "Generic text"
    }
}

3. set flutter: generate: true in pubspec.yaml, create an empty l10n.yaml in project root
4. run flutter run or flutter gen-l10n
   Expected results: Everything is translated, no message
   Actual results: Right after starting the build the first message in console is:

To see a detailed report, use the --untranslated-messages-file 
option in the tool to generate a JSON format file containing 
all messages that need to be translated.

• --untranslated-messages-file flag doesn't generate any file
• --gen-inputs-and-outputs-list file doesn't contain the untranslated-messages-file

Appeared in 1.22.0 release

Logs

%USERPROFILE%\DEV\files\flutter\gen_l10n_bug>flutter gen-l10n --untranslated-messages-file file.json -v
[ +184 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[ +154 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[   +1 ms] d408d302e22179d598f467e11da5dd968dbdc9ec
[   +2 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git tag --points-at HEAD
[ +145 ms] Exit code 0 from: git tag --points-at HEAD
[   +1 ms] 1.22.0
           1.22.0-12.3.pre
[  +22 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[ +125 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[   +1 ms] origin/stable
[        ] executing: [%USERPROFILE%\DEV\tools\flutter/] git ls-remote --get-url origin
[  +91 ms] Exit code 0 from: git ls-remote --get-url origin
[   +1 ms] https://github.com/flutter/flutter.git
[ +159 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git rev-parse --abbrev-ref HEAD
[  +78 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[   +1 ms] stable
[ +175 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[  +51 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[  +29 ms] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[  +23 ms] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[  +13 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[  +24 ms] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[   +3 ms] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[  +25 ms] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +50 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
[   +9 ms] Artifact Instance of 'GradleWrapper' is not required, skipping update.
[   +4 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[  +40 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[  +24 ms] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +2 ms] Artifact Instance of 'FlutterSdk' is not required, skipping update.
[  +55 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[  +34 ms] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[   +6 ms] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[  +29 ms] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[   +1 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[  +47 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +2 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +2 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[  +26 ms] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
[ +370 ms] "flutter gen-l10n" took 914ms.
[ +269 ms] ensureAnalyticsSent: 258ms
[   +3 ms] Running shutdown hooks
[  +16 ms] Shutdown hooks complete
[   +1 ms] exiting with code 0

%USERPROFILE%\DEV\files\flutter\gen_l10n_bug>flutter gen-l10n -v                                        
[ +202 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[ +134 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[   +1 ms] d408d302e22179d598f467e11da5dd968dbdc9ec
[   +2 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git tag --points-at HEAD
[ +135 ms] Exit code 0 from: git tag --points-at HEAD
[   +1 ms] 1.22.0
           1.22.0-12.3.pre
[  +47 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[ +140 ms] Exit code 0 from: git rev-parse --abbrev-ref --symbolic @{u}
[   +1 ms] origin/stable
[        ] executing: [%USERPROFILE%\DEV\tools\flutter/] git ls-remote --get-url origin
[  +82 ms] Exit code 0 from: git ls-remote --get-url origin
[   +1 ms] https://github.com/flutter/flutter.git
[ +201 ms] executing: [%USERPROFILE%\DEV\tools\flutter/] git rev-parse --abbrev-ref HEAD
[  +90 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[   +1 ms] stable
[ +159 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[   +2 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' is not required, skipping update.
[   +2 ms] Artifact Instance of 'AndroidInternalBuildArtifacts' is not required, skipping update.
[  +23 ms] Artifact Instance of 'IOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[  +11 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[  +32 ms] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[  +57 ms] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[  +49 ms] Artifact Instance of 'MaterialFonts' is not required, skipping update.
[   +2 ms] Artifact Instance of 'GradleWrapper' is not required, skipping update.
[   +1 ms] Artifact Instance of 'AndroidMavenArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'AndroidGenSnapshotArtifacts' 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.
[  +44 ms] Artifact Instance of 'FlutterWebSdk' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterSdk' is not required, skipping update.
[   +1 ms] Artifact Instance of 'WindowsEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'MacOSEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'LinuxEngineArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'LinuxFuchsiaSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'MacOSFuchsiaSDKArtifacts' is not required, skipping update.
[  +77 ms] Artifact Instance of 'FlutterRunnerSDKArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FlutterRunnerDebugSymbols' is not required, skipping update.
[   +1 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[  +45 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[        ] Artifact Instance of 'IosUsbArtifacts' is not required, skipping update.
[   +1 ms] Artifact Instance of 'FontSubsetArtifacts' is not required, skipping update.
[ +338 ms] To see a detailed report, use the --untranslated-messages-file 
                    option in the tool to generate a JSON format file containing 
                    all messages that need to be translated.
[  +64 ms] "flutter gen-l10n" took 785ms.
[ +300 ms] ensureAnalyticsSent: 263ms
[   +3 ms] Running shutdown hooks
[  +18 ms] Shutdown hooks complete
[   +1 ms] exiting with code 0

[√] Flutter (Channel stable, 1.22.0, on Microsoft Windows [Version 10.0.20221.1000], locale en-150)
    • Flutter version 1.22.0 at C:\Users\sominemo\DEV\tools\flutter
    • Framework revision d408d302e2 (3 days ago), 2020-09-29 11:49:17 -0700
    • Engine revision 5babba6c4d
    • Dart version 2.10.0

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
    • Android SDK at C:\Users\sominemo\AppData\Local\Android\sdk
    • Platform android-30, build-tools 30.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)
    • All Android licenses accepted.

[√] Android Studio (version 4.0)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 47.1.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[√] VS Code, 64-bit edition (version 1.49.2)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension version 3.15.0

[√] Connected device (1 available)
    • Pixel 4 (mobile) • 9A231FFAZ006J5 • android-arm64 • Android 11 (API 30)

• No issues found!

[TahaTesser]

Hi @Sominemo
I can reproduce the issue

logs

[ +119 ms] To see a detailed report, use the --untranslated-messages-file 
                    option in the tool to generate a JSON format file containing 
                    all messages that need to be translated.

flutter doctor -v

[✓] Flutter (Channel stable, 1.22.0, on Linux, locale en_US.UTF-8)
    • Flutter version 1.22.0 at /home/tahatesser/Code/flutter_stable
    • Framework revision d408d302e2 (6 days ago), 2020-09-29 11:49:17 -0700
    • Engine revision 5babba6c4d
    • Dart version 2.10.0

 
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /home/tahatesser/Code/sdk
    • Platform android-30, build-tools 30.0.2
    • ANDROID_HOME = /home/tahatesser/Code/sdk
    • Java binary at: /home/tahatesser/Code/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Android Studio (version 4.0)
    • Android Studio at /home/tahatesser/Code/android-studio
    • Flutter plugin version 50.0.1
    • Dart plugin version 193.7547
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.49.3)
    • VS Code at /usr/share/code
    • Flutter extension version 3.15.0

[✓] Connected device (1 available)
    • Android SDK built for x86 (mobile) • emulator-5554 • android-x86 • Android
      10 (API 29) (emulator)

• No issues found!

flutter doctor -v

[✓] Flutter (Channel master, 1.23.0-8.0.pre.130, on Linux, locale en_US.UTF-8)
    • Flutter version 1.23.0-8.0.pre.130 at /home/tahatesser/Code/flutter_master
    • Framework revision f4bad5b422 (16 hours ago), 2020-10-04 12:37:03 -0400
    • Engine revision 04a46cc656
    • Dart version 2.11.0 (build 2.11.0-185.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /home/tahatesser/Code/sdk
    • Platform android-30, build-tools 30.0.2
    • ANDROID_HOME = /home/tahatesser/Code/sdk
    • Java binary at: /home/tahatesser/Code/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop
    • clang version 10.0.0-4ubuntu1
    • cmake version 3.16.3
    • ninja version 1.10.0
    • pkg-config version 0.29.1

[✓] Android Studio (version 4.0)
    • Android Studio at /home/tahatesser/Code/android-studio
    • Flutter plugin version 50.0.1
    • Dart plugin version 193.7547
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.49.3)
    • VS Code at /usr/share/code
    • Flutter extension version 3.15.0

[✓] Connected device (4 available)
    • Android SDK built for x86 (mobile) • emulator-5554 • android-x86    • Android 10 (API 29) (emulator)
    • Linux (desktop)                    • linux         • linux-x64      • Linux
    • Web Server (web)                   • web-server    • web-javascript • Flutter Tools
    • Chrome (web)                       • chrome        • web-javascript • Google Chrome 85.0.4183.121

• No issues found!

[HansMuller]

CC @shihaohong

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.