Reproductions should be small, self-contained, correct examples – http://sscce.org. For example, if your bug isn't related to Gulp, **do not include Gulp in the repro**. (Side-note: if it *is* related to Gulp, this is the wrong issue tracker!) If possible, use a config file as it's the standard, favoured approach to using Rollup: https://github.com/rollup/rollup/wiki/Command-Line-Interface#using-a-config-file
Occasionally, this won't be possible, and that's fine – we still appreciate you raising the issue. But please understand that Rollup is run by unpaid volunteers in their free time, and we will prioritise bugs that follow these instructions.
If you have a stack trace to include, we recommend putting inside a `<details>` block for the sake of the thread's readability: