Custom bundle via rollup is broken

[Turbo87]

I'm trying to generate a custom bundle of D3 v4 using rollup:

https://github.com/Turbo87/rollup-d3-issue

Running npm run build (or rollup -c) will produce a bundled file at dist/d3.js which looks fine on first glance. It includes the following function call:

defaultLocale({
  decimal: ".",
  thousands: ",",
  grouping: [3],
  currency: ["$", ""]
});

but the defaultLocale() function is not defined anywhere in the bundle even though it's in the original code (at https://github.com/d3/d3-format/blob/v1.0.2/src/defaultLocale.js).

Note that if I add export { formatDefaultLocale } from 'd3-format'; to the d3.js file we can work around this issue. This is not a good long-term solution though.

Cross-posted this as rollup/rollup#970

[mbostock]

Thanks for filing an issue. This is clearly a Rollup bug, so I’ll close this and reply over there if I have any insight. Sorry for the inconvenience.