Hi.
This is an friendly, semi-autogenerated, reminder that plan(multiprocess) of the future package is deprecated since future 1.20.0 (2020-11-03). It will eventually become defunct and removed. The background for this can be found in HenrikBengtsson/future#420.
Your varimpact package relies on, or recommends to use, multiprocess, cf. https://github.com/twolodzko/varimpact/search?q=multiprocess.
Thank you,
Henrik (maintainer of the future package)