su: ignoring --preserve-environment, it's mutually exclusive with --login
Downloading GitHub repo celehs/kesernetwork@addgroup
Installing package into ‘/usr/local/lib/R/site-library’
(as ‘lib’ is unspecified)
Warning in i.p(...) :
  'lib = "/usr/local/lib/R/site-library"' is not writable
Error: Failed to install 'kesernetwork' from GitHub:
  unable to install packages
Execution halted