Green Man have announced details of their 20th anniversary festival, revealing Michael Kiwanuka as their first headliner for 2022.After cancelling their 2020 festival due to COVID-19, Green Man returned to the Brecon Beacons last month for its 2021 edition.2020 Mercury Prize winner Kiwanuka was set to headline Green Man 2020, before being replaced by Caribou, Fontaines D.C.