gradlew commands fail with: "failed to find target with hash string 'android-N'"

[cirosantilli]

I have already installed SDK 23 and 24 through Studio, created a working API 24 emulator, and have NDK 12.

Whenever I run a gradlew command, e.g.:

cd tutorial01_load_vulkan
./gradlew clean

it fails with:

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':app'.
> Exception thrown while executing model rule: NdkComponentModelPlugin.Rules#createNativeLibrary > create(vktuts) > components.vktuts.getBinaries() > withType()
   > Exception thrown while executing model rule: BaseComponentModelPlugin.Rules#createAndroidComponents
      > failed to find target with hash string 'android-N' in: /home/ciro/android-sdk

Same error message on SO: http://stackoverflow.com/questions/35937530/android-studio-2-1-preview-failing-to-find-target-with-hash-string-android-n