Build failed after updating tools for Android L

Question

I cannot build my project after updating the tools. I get this error in Android Studio.

/build/exploded-aar/com.android.support/support-v4/21.0.0-rc1/And

Answer 1

In your app/build.gradle file, change
compile 'com.android.support:support-v4:+'
to
compile 'com.android.support:support-v4:19.1.0'

The '+' means that it will look for the newest version of the dependency. If you download the L preview, the latest version will be the support library for L - which isn't going to work for a project whose target is API 19.