The latest factory images for the Nexus family have landed and people are getting their updates. What are they updating to? The changelogs built from developer comments can probably answer that, or at least give some pretty good hints.

Like most of the monthly updates, at least since Google started this practice, March's update focuses on security. Google already posted a detailed accounting of the security issues addressed with this release, and most of the changelogs appear to line up almost exactly. We're not going to find much in the way of performance improvements or bug fixes for usability problems. At least, they won't come from AOSP itself—it's always possible the proprietary binaries have their own fixes, and those changes aren't usually detailed in AOSP.

There is one outlier in the list: the MHC19J factory image for the Nexus 5X. It uses a version of Android v5.1.1 as a base and cherry picks basically all of the changes up through v6.0.1_r22. Like any update, it includes all of the recent security updates, and most or all of the previous fixes of that nature. The unfortunate side effect of this technique is it results in a massive changelog with a ton of entries we've seen in previous changelogs. I've been able to filter out most of the duplicates once or twice in the past, but it's not as easy with this one, so it's pretty tough to identify which commits are new and which ones we've seen before. I've still got plans to fix this in the future, but time hasn't been on my side. Nevertheless, if there's something specific you're looking for, it's probably searchable.

The Nexux 6P received its own special build like the 5X. It comes in as android-6.0.1_r21 and takes a place directly before the r22 update that showed up yesterday. As such, the new r22 changelog is basically just a bump in build number from the r21 version.

Take a look at the changelogs below. They are all pretty short, except for the last one. Drop a comment below if anything interesting turns up in the exploration!

Added LMY49I Changelog

Another changelog was released for Android 5.1.1 on the Nexus 5 and 6 with the build number LMY49I. There's not much to it, but it's here for reference.