Dagger, a Java dependency injection framework, has just released version 2.0 and I thought I would try my hand at migrating my Android app, which is using 1.0, to the new version. It took me a few hours on an small-ish app with 3 activities, 6 fragments, 3 singleton services and 2 dagger modules (Application-level and activity-level). This was mostly because I used a fair bit of time banging my head against a brick war. To be fair, 90% of the conversion was smooth, but the 10% really had me lost. I will lay out some of the brick walls I ran into. The Dagger 2.0 website already have a migration guide which is good starting point. This blog post is meant to be a supplement to that.