[cageface]

It has also created havoc in the Swift world. Suddenly all existing Swift code is broken. The migration tool is supposed to take care of most of this for you but my experience has been that it misses a lot of things and upgrading requires many manual fixes. Of course every Swift library in existence also needs to be updated so your changes of a smooth migration right now are slim.

Apple has the resources to push this through and developers don't really have much choice so I don't expect this to become another Python 3 fiasco but this really should be the last time Apple breaks so much code just to clean up the syntax a bit.