After typing cordova run android in terminal, I'm getting this error:

Waiting for emulator to start...
PANIC: Broken AVD system path. Check your ANDROID_SDK_ROOT value [/Users/username/Library/Android/sdk]!

This happens after exporting:

export ANDROID_SDK_ROOT='/Users/username/Library/Android/sdk'

Before exporting I got:

Waiting for emulator to start...
PANIC: Cannot find AVD system path. Please define ANDROID_SDK_ROOT

Any ideas where I'm going wrong? I'm sure this is the sdk root so why am I getting broken avd system path?