Надо заменить ключ snowmix. Выложено на http://git.altlinux.org/people/snowmix/private/alt-gpgkeys.git, commit 12ffae76bf0c9b45a9a965ddb0691d65bcbac14f.
alt-gpgkeys-0.7.168-alt1 -> sisyphus: Fri Jan 31 2020 Gleb F-Malinovskiy <glebfm@altlinux> 0.7.168-alt1 - Replaced key: snowmix@ (4DE2462A -> E2F5E034; closes: #37955). - Updated key: bircoph@ (5372756C; closes: #37932). Mon Jan 20 2020 Gleb F-Malinovskiy <glebfm@altlinux> 0.7.167-alt1 - Updated expired keys: + x09@ (0C16659B; see: #34359); + naf@ (DD7132A6; closes: #37772).