Flutter project build failed with error message:-

Question

Build file 'C:\Users\amani\Desktop\expenseapp\android\build.gradle' line: 24

* What went wrong:
A problem occurred evaluating root project 'android'.
> A problem occurred configuring project ':app'.
   > Failed to find target with hash string 'android-28' in: C:\Users\amani\AppData\Local\Android\Sdk

* 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.

Launching lib\main.dart on ALE L21 in debug mode...

FAILURE: Build failed with an exception.

* Where:
* Get more help at https://help.gradle.org

BUILD FAILED in 2s
Gradle task assembleDebug failed with exit code 1
Exited (sigterm)

And android\build.gradle is as follows:

buildscript {
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(':app')
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Could anyone help me to solve this problem? I've tried many other solutions I found online but nothing seems to work and I can't figure out what to do to make this work.

Running the flutter doctor command returns this:

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, v1.12.13+hotfix.5, on Microsoft Windows [Version 10.0.18363.592], locale en-US)

[√] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
[√] Android Studio (version 3.5)
[√] VS Code (version 1.41.1)
[√] Connected device (1 available)

• No issues found!

Solution

In your android/app/build.gradle file, change the compileSdkVersion from 28 to 29 and targetSdkVersion from 28 to 29.

Then, rebuild the project again.

Comments

[Aamil Silawat]

if you are using android studio, try using flutter clean command in terminal and then rebuild project

[Darish]

@AmaniSaaduddin open the android folder alone in android studio and try to build, there you will get the exact reason that will help you to resolve it.

[Amani Saaduddin]

Thanks for making time and answering, I updated my Android SDK and istalled JDK 8 and now it works fine.

[Darish]

@AmaniSaaduddin Feel free to accept my answer if you think it helped. Thank you.