ionic 2 - Error Could not find an installed version of Gradle either in Android Studio
Life is too short to spend it on messing with paths, etc.
Since I had Homebrew installed on the iMac, I just ran this command:
brew install gradle
The Ionic3 project started to build successfully.
Try installing gradle and include it into your path. Click the link below to get manual. https://gradle.org/install
Just install gradle on linux, Even if Android Studio is installed,
sudo apt install gradle