https://rollupjs.org/repl?version=0.61.0&shareable=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

If undefined is used in multiple modules, it is renamed to undefined$0 with a number after the dollar sign to avoid naming collisions. In this case though, undefined should not be renamed.

This bug was introduced in v0.61.0, we didn't have this problem in v0.60.7