When I run ionic build android command in root of ionic project, I am getting this error:
FAILURE: Build failed with an exception.
For me, the problem was that ANDROID_HOME was pointing to an old Android SDK path. After installing Android Studio, I had to update ~/.bash_profile accordingly for MAC (El Capitan)
export ANDROID_HOME="/Users/corneliusparkin/Library/Android/sdk"
Remember to re-start terminal or run this command after updating ~/.bash_profile
source ~/.bash_profile