FlutterPlugin.kt and FlutterPluginUtils.kt error while running project in Flutter 3.32.0

Question

Hi I started getting error after I upgraded my Flutter version in MacOS Sequioa (15.5 (24F74)

Running Gradle task 'assembleDebug'...
e: file:///Users/.../development/flutter/packages/flutter_tools/gradle/src/main/kotlin/FlutterPlugin.kt:715:21 Unresolved reference 'fileMode'.
e: file:///Users/.../development/flutter/packages/flutter_tools/gradle/src/main/kotlin/FlutterPluginUtils.kt:67:61 'fun String.toLowerCase(): String' is deprecated. Use lowercase() instead.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':gradle:compileKotlin'.
> A failure occurred while executing org.jetbrains.kotlin.compilerRunner.GradleCompilerRunnerWithWorkers$GradleKotlinCompilerWorkAction
   > Compilation error. See log for more details

android/build.gradle:

buildscript {
    ext.kotlin_version = '1.9.0'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

rootProject.buildDir = '../build'
subprojects {
     afterEvaluate { project ->
        if (project.plugins.hasPlugin("com.android.application") ||
                project.plugins.hasPlugin("com.android.library")) {
            project.android {
                compileSdkVersion 36
                buildToolsVersion "36.0.0"
            }
        }
    }
    project.buildDir = "${rootProject.buildDir}/${project.name}"
    project.evaluationDependsOn(':app')
}

tasks.register("clean", Delete) {
    delete rootProject.buildDir
}

I tried solving compiler issues in both files as suggested by Dhrumil Parikh but got following issue:

Build file '/Users/../Flutter App/android/build.gradle' line: 32. This line is project.evaluationDependsOn(':app')

Flutter details:

Flutter 3.32.0 • channel stable • https://github.com/flutter/flutter.git Framework • revision be698c48a6 (3 days ago) • 2025-05-19 12:59:14 -0700 Engine • revision 1881800949 (3 days ago) • 2025-05-19 10:54:07 -0700 Tools • Dart 3.8.0 • DevTools 2.45.1

Answer 1

In Flutter App/android/build.gradle, use:

ext.kotlin_version = '2.1.21'

In gradle-wrapper.properties, use:

distributionUrl=https\://services.gradle.org/distributions/gradle-8.14.1-bin.zip

In pubspec.yaml:

Upgrade the package intl to ^0.20.2 if you are using it

and (optional) use:

flutter:  
    generate: true