Launchpad: addComponentAsRefTo Error

[Wellington Cordeiro]

Copying over from firefox-devtools/debugger#4479 courtesy of @darkwing

Every time I update to this repo's master to get the new patches, then do a yarn install, I see the following in the launchpad (http://localhost:8000):

Error: addComponentAsRefTo(...): Only a ReactOwner can have refs. You might be adding a ref to a component that was not created inside a component's `render` method, or you have multiple copies of React loaded (details: https://fb.me/react-refs-must-have-owner).  invariant.js:42

I can rm -rf node_modules && yarn nom but this issue isn't going away so I presume there's a real problem somewhere.