The following fails in a fresh environment:

remotes::install_bioc("Biostrings")

with

Error: package ‘XVector’ 0.20.0 was found, but >= 0.21.4 is required by ‘Biostrings’

Remotes is installing XVector 0.20.0 instead of the latest (0.22.0).

Remotes: 2.0.2
Platform: Mac

For a fresh environment, I'm using packrat::init(); install.packages("remotes").