Gradle is already install, and set in the path
but, went I build flutter module, flutter will download gradle again

whereis gradle

gradle: /root/.sdkman/candidates/gradle/6.7/bin/gradle.bat /root/.sdkman/candidates/gradle/6.7/bin/gradle

echo $PATH

/usr/local/git/bin:/usr/local/go/bin:/go/bin:/root/.sdkman/candidates/kotlin/current/bin:/root/.sdkman/candidates/gradle/current/bin:/root/.sdkman/candidates/maven/current/bin/:/usr/lib64/ccache:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/Flutter/bin:/usr/local/Flutter/bin/cache/dart-sdk/bin

gradle --version

Gradle 6.7

Build time: 2020-10-14 16:13:12 UTC
Revision: 312ba9e0f4f8a02d01854d1ed743b79ed996dfd3

Kotlin: 1.3.72
Groovy: 2.5.12
Ant: Apache Ant(TM) version 1.10.8 compiled on May 10 2020
JVM: 1.8.0_291 (Oracle Corporation 25.291-b10)
OS: Linux 5.10.25-linuxkit amd64

flutter doctor -v

[✓] Flutter (Channel unknown, 2.2.1, on Linux, locale zh_CN.UTF-8)
• Flutter version 2.2.1 at /usr/local/Flutter
• Framework revision 02c026b (3 周前), 2021-05-27 12:24:44 -0700
• Engine revision 0fdb562ac8
• Dart version 2.13.1
• Pub download mirror https://pub.flutter-io.cn
• Flutter download mirror https://storage.flutter-io.cn

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
• Android SDK at /opt/app/android-sdk
• Platform android-29, build-tools 29.0.2
• ANDROID_HOME = /opt/app/android-sdk
• Java binary at: /usr/java/jdk1.8.0_291-amd64/bin/java
• Java version Java(TM) SE Runtime Environment (build 1.8.0_291-b10)
• All Android licenses accepted.

[✗] Chrome - develop for the web (Cannot find Chrome executable at google-chrome)
! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[!] Android Studio (not installed)
• Android Studio not found; download from https://developer.android.com/studio/index.html
(or visit https://flutter.dev/docs/get-started/install/linux#android-setup for detailed instructions).

[!] Connected device
! No devices available

env

ANDROID_HOME=/opt/app/android-sdk
FLUTTER_ROOT=
JAVA_HOME=/usr/java/jdk1.8.0_291-amd64
GRADLE_HOME=/root/.sdkman/candidates/gradle/current

flutter build aar --no-debug --no-profile --target-platform android-arm64 -v

[ +23 ms] executing: [/data/landun/workspace/trovo_flutter/.android/] /data/landun/workspace/trovo_flutter/.android/gradlew
-I=/usr/local/Flutter/packages/flutter_tools/gradle/aar_init_script.gradle -Pflutter-root=/usr/local/Flutter -Poutput-dir=/data/landun/workspace/trovo_flutter/build/host
-Pis-plugin=false -PbuildNumber=1.0 -Pverbose=true -Pdart-obfuscation=false -Ptrack-widget-creation=true -Ptree-shake-icons=true -Ptarget-platform=android-arm64
assembleAarRelease
[+6009 ms] Downloading https://services.gradle.org/distributions/gradle-6.7-all.zip