`parallel` is a basic R pacakge and should be at the same version as R so if you ask for R>=3.6 `parallel` should also be 3.6: https://github.com/VincyaneBadouard/LoggingLab/blob/e6a8f70acb2af5d7aebc9b272336c4a5e14a10c7/DESCRIPTION#L42 https://github.com/VincyaneBadouard/LoggingLab/blob/e6a8f70acb2af5d7aebc9b272336c4a5e14a10c7/DESCRIPTION#L67