Flutter project fails to build when gradle gets upgraded. Error: Type 'FlutterTask' property 'assets' is missing an input or output annotation

Question

When I try to build my application on a usb device, the build crashes displaying this log output

FAILURE: Build failed with an exception.

• What went wrong: Some problems were found with the configuration of task ':app:compileFlutterBuildDebug' (type 'FlutterTask').

  • Type 'FlutterTask' property 'assets' is missing an input or output annotation.

    Reason: A property without annotation isn't considered during up-to-date checking.

    Possible solutions:

    1. Add an input or output annotation.
    2. Mark it as @Internal.

    Please refer to https://docs.gradle.org/7.0/userguide/validation_problems.html#missing_annotation for more details about this problem.

  • Type 'FlutterTask' property 'assetsDirectory' is missing an input or output annotation.

    Reason: A property without annotation isn't considered during up-to-date checking.

    Possible solutions:

    1. Add an input or output annotation.
    2. Mark it as @Internal.

    Please refer to https://docs.gradle.org/7.0/userguide/validation_problems.html#missing_annotation for more details about this problem.

  • Type 'FlutterTask' property 'buildMode' is missing an input or output annotation.

    Reason: A property without annotation isn't considered during up-to-date checking.

    Possible solutions:

    1. Add an input or output annotation.
    2. Mark it as @Internal.

    Please refer to https://docs.gradle.org/7.0/userguide/validation_problems.html#missing_annotation for more details about this problem.

  • Type 'FlutterTask' property 'fastStart' doesn't have a configured value.

    Reason: This property isn't marked as optional and no value has been configured.

    Possible solutions:

    1. Assign a value to 'fastStart'.
    2. Mark property 'fastStart' as optional.

    Please refer to https://docs.gradle.org/7.0/userguide/validation_problems.html#value_not_set for more details about this problem.

  • Type 'FlutterTask' property 'flutterExecutable' is missing an input or output annotation.

    Reason: A property without annotation isn't considered during up-to-date checking.

    Possible solutions:

    1. Add an input or output annotation.
    2. Mark it as @Internal.

    Please refer to https://docs.gradle.org/7.0/userguide/validation_problems.html#missing_annotation for more details about this problem.

• Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 1s Exception: Gradle task assembleDebug failed with exit code 1

Please help to find a solution to this problem

Solution

This is happening because you updated gradle in your project to gradle 7. And gradle 7 has some new annotation property which must be reviewed.

I also faced this and filed an issue on github. This is the link

So the choice you have

1. Downgrade your gradle( < 7 )
2. Make changes as mentioned in this PR.

In the referred page(Pull Req) . There is a section named Files Changed. See the green colored lines over there. Just edit your gradle file and add/edit same as green colored lines.

Comments

[Nikhil Badyal]

Go to android->gradle->wrapper->gradle-wrapper.properties in the last line change 7.0-all to 6.7-all or whatever you want

[theINtoy]

./gradlew wrapper --gradle-version 6.8.3 will roll back to the last 6.x version released

[Mohammad Hadi]

it is a temporary solution, we can't use old version for ever, how we can solve this problem with gradle >= 7

[Nikhil Badyal]

@MohammadHadi It's(2nd solution) not a temporary solution. Please care to read my answer CAREFULLY. I have referred a PR which solves the issue.

[Slamit]

Thank you for the link to the PR, miroring it worked perfectly!

[Joel G Mathew]

@ProblematicDude Kindly make your answer more descriptive. What exactly do you mean by make changes as per the PR? Which file to change?

[Nikhil Badyal]

@JoelGMathew Sure