Changed previous error message from:
> Cannot read from mutable source during the current render without tearing. This is a bug in React. Please file an issue.
To:
> Cannot read from mutable source during the current render without tearing. This may be a bug in React. Please file an issue.
Also added a DEV only warning about the unsafe side effect:
> A mutable source was mutated while the %s component was rendering. This is not supported. Move any mutations into event handlers or effects.
I think this is the best we can do without adding production overhead that we'd probably prefer to avoid.