Failed to find target with hash string 'android-25', though android-25 is actually installed

Question

I have a Ubuntu Xenial VM running in OpenStack, there I've downloaded the latest Android SDK tools ( tools_r25.2.3-linux.zip ) from https://developer.android.com/studio/index.html. And everything is well configured:

• JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
• ANDROID_HOME=<ANDROID_SDK_PATH>
• PATH=${PATH}:${ANDROID_HOME}
• echo "sdk.dir=<ANDROID_SDK_PATH>" > <MY_ANDROID_PROJECT_PATH>/local.properties

But when try to execute task: ./gradlew clean, error occurs:

Preparing "Install Android SDK Build-Tools 25".
Warning: Trying to install into ${ANDROID_HOME}/build-tools/25.0.0/ but package "Android SDK Tools 25.2.4" already exists at ${ANDROID_HOME}. It must be deleted or moved away before installing into a child directory.
Preparing "Install Android SDK Platform 25".
Warning: Trying to install into ${ANDROID_HOME}/platforms/android-25/ but package "Android SDK Tools 25.2.4" already exists at ${ANDROID_HOME}. It must be deleted or moved away before installing into a child directory.

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':demo'.
> Failed to install the following SDK components:
  [Android SDK Build-Tools 25, Android SDK Platform 25]
  Please install the missing components using the SDK manager in Android Studio.

And actually as the error log mentions, I have the required tools installed. Run $ANDROID_HOME/bin/sdkmanager --list shows my installed packages:

Installed packages:
  Path                        | Version | Description                       | Location
  -------                     | ------- | -------                           | -------
  build-tools;25.0.0          | 25.0.0  | Android SDK Build-Tools 25        | build-tools/25.0.0/
  extras;android;m2repository | 41.0.0  | Android Support Repository, re... | extras/android/m2repository/
  platform-tools              | 25.0.2  | Android SDK Platform-Tools 25.0.2 | platform-tools/
  platforms;android-25        | 3       | Android SDK Platform 25, rev 3    | platforms/android-25/
  tools                       | 25.2.4  | Android SDK Tools 25.2.4          | tools/

What could be wrong here? I'm a bit suspicious of the SDK path here.

Answer 1

Just confirmed my speculation - this is due to the new change made in the latest Android SDK release.

Thanks god we have a time machine, so that we can go back to see what exactly happened (can't really find any cue from SDK Tools Release Notes).

• SDK download page on 2016.12.06 and the SDK file: android-sdk_r24.4.1-linux.tgz
• SDK download page on 2016.12.09 and the SDK file: tools_r25.2.3-linux.zip

Let's have a look at the file structures of ANDROID_HOME before and after the change.

Before:

android-sdk-linux
├── SDK Readme.txt
├── add-ons (empty)
├── platforms (empty)
└── tools
    ├── a bunch of preloaded tools
    ├── ...
    └── ...

After:

tools
├── a bunch of preloaded tools
├── ...
└── ...

No more add-ons or platforms, only the tools as the new root directory.

Problem: Gradle will be confused if you set the $ANDROID_HOME directly to the unzipped top-most tools directory.

Solution: After unzip the new SDK file (you'll get a tools directory), create another directory (e.g. android-sdk), and move the tools directory completely inside the empty android-sdk, then set environment variables as:

ANDROID_HOME=/android-sdk
PATH=${PATH}:${ANDROID_HOME}/tools

In short: DON'T set $ANDROID_HOME directly to the new tools parent directory, wrap it inside another parent!