From 9f0a9317d328b58f8dd55173abd38ce1db80cfd0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EB=A5=98=EC=A4=80=EC=98=81?=
 <mimyo@lyujun-yeong-ui-Macmini.local>
Date: Fri, 28 Aug 2026 17:50:39 +0900
Subject: [PATCH] Support AGP 9 built-in Kotlin
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AGP 9 ships built-in Kotlin support and registers its own `kotlin { }`
extension. Unconditionally applying the classic 'kotlin-android' plugin
on top of it fails ("no longer required for Kotlin support since AGP 9"),
which currently blocks apps that adopt AGP 9 with built-in Kotlin enabled
from depending on this plugin.

Only apply 'kotlin-android' when it's actually needed: on AGP < 9, or on
AGP 9+ where the app has explicitly opted out via
`android.builtInKotlin=false` (Flutter's current recommended interim
state for AGP 9 adopters). Move the jvmTarget configuration to the
top-level `kotlin { compilerOptions { } }` block per Flutter's plugin
migration guide, since that extension is present in both cases.

Verified against a real Flutter app on AGP 9.0.1 / Gradle 9.1.0 with
`android.builtInKotlin=false` (today's supported "opt-out" combination)
— `flutter build appbundle --release` succeeds with this change, with
no change in output versus the current published version. The
`builtInKotlin=true` path (Flutter 3.47+) follows AGP's documented
built-in Kotlin behavior but wasn't independently build-tested since it
requires a newer Flutter SDK than what's available in the test app.

See https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors
---
 android/build.gradle | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/android/build.gradle b/android/build.gradle
index a37bb9678..16d294d76 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -25,7 +25,17 @@ rootProject.allprojects {
 }
 
 apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+
+// AGP 9+ ships built-in Kotlin support and registers its own `kotlin { }` extension,
+// which conflicts with the classic 'kotlin-android' plugin unless the app has opted
+// out via `android.builtInKotlin=false` in gradle.properties (Flutter's current
+// recommended interim state; see https://docs.flutter.dev/release/breaking-changes/migrate-to-built-in-kotlin/for-plugin-authors).
+def agpMajor = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION.tokenize('.')[0] as int
+def builtInKotlinOptedOut = project.hasProperty('android.builtInKotlin') &&
+        !Boolean.parseBoolean(project.property('android.builtInKotlin').toString())
+if (agpMajor < 9 || builtInKotlinOptedOut) {
+    apply plugin: 'kotlin-android'
+}
 
 android {
     namespace "dev.note11.flutter_naver_map.flutter_naver_map"
@@ -37,10 +47,6 @@ android {
         targetCompatibility JavaVersion.VERSION_1_8
     }
 
-    kotlinOptions {
-        jvmTarget = '1.8'
-    }
-
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
     }
@@ -54,3 +60,9 @@ android {
         implementation 'com.google.android.gms:play-services-location:21.3.0'
     }
 }
+
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_1_8
+    }
+}