Transition throwing 'too late' error in react

[noahehall]

playing around with transitions for a udacity project, and i started getting these 'too late' errors when overing over a bar chart

relavant code is here: https://github.com/noahehall/udacity-corporate-dashboard/blob/piecharts/src/components/charts/examples.js#L155

error im getting:

linking to this in codebase:

[mbostock]

This means you are trying to modify a transition that has already started, or derive a transition from one that has ended. Please read the API Reference section on transition life cycles.

[noahehall]

thanks @mbostock