Upgrade to 1.2.1 broke React.addons?

I updated Meteor from to 1.2.1 using “meteor update”, and I’m now getting the error:

“Uncaught TypeError: React.addons.cloneWithProps is not a function”

(I’m using React.addons.cloneWithProps in my code.) Downgrading back to did not fix the issue, which is disturbing. Not sure how to proceed to get my app back to a functioning state.

UPDATE: Can’t repro this with a simple test application, which is even weirder. PEBCAK? Will update this with more info if I can figure it out, but if anybody had weird React issues after updating, please let me know.

React.addons.cloneWithProps was deprecated, and I guess is no longer available with the upgraded version of React that ships with 1.2.1. Should be using React.cloneElement instead. Herp derp!