Gmail is undeniably one of the bigger draws of Android, and now that the app is compatible with more than just Google Apps and gmail.com addresses, it's only become a more integral part of Google's mobile platform. Of course, Gmail isn't the only email app available on Android and there's a good deal of very good options to choose from. For those running stock Android on a Nexus device, it's no surprise that Gmail has been the preferable choice for a long time now. Which is why the recently-discovered sync bug on Nexus devices running Android 6.0 Marshmallow was a real pain for a lot of users. Now, Google is rolling out a fix, and there's no update required, either.
The bug reared its ugly head at the beginning of the year, and since then it's been a known issue in the AOSP Issue Tracker. Now, Google has apparently found the root cause of the issue and will be rolling out an update. As per the note from Googler Orrin: "I'm happy to announce that a fix has started to roll out. This fix requires no action, and will roll out globally over the next week." Orrin goes on to clarify and confirm that "the fix will not come through a system update, hence there is no OTA file or anything like that." This pretty much confirms that the issue will be fixed server side and won't be part of the February security updates OTA that should be hitting Nexus devices real soon. An app update isn't entirely out of the question, as a recent fix rolled out for those experiencing issues with Hotmail accounts, but it appears Google have more control over their own Gmail platform and can perform a fix server side.
This has been an interesting bug to see from Google, and one that you wouldn't expect to see from someone like Google, but mistakes do happen and the important thing is that Google has found the root cause and will be sending out fixes to ensure those affected get back online with their email. It would seem the only way to see if the fix is final would be to keep checking your Gmail, Google say the fix will be complete in about a week or so.