IssueTracker

Specifying -printmapping in proguard-rules.pro has no effect in generating mapping file in new Android Studio (tested on 2.0.0-beta5 and 2.1.0-alpha3 )

Inside build.gradle:
buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

Inside proguard-rules.pro:
-printmapping proguard-mapping.txt

In previous Android Studio versions mapping file specified using printmapping got generated at the root folder of the project. Mapping file is generated in a default location at build/output folder but it ignores printmapping option so now you cannot give it a custom name or location at build time.