$ R_LIBS_SITE=/path/unknown R --quiet --no-environ
Warning messages:
1: startup::check(): Environment variable 'R_LIBS_SITE' specifies a non-existing folder '/path/unknown' which R ignores and therefore are not used in .libPaths(). To create this folder, call dir.create("/path/unknown", recursive = TRUE)
2: startup::check(): Environment variable 'R_LIBS_SITE' specifies a non-existing folder '/path/unknown' which R ignores and therefore are not used in .libPaths(). To create this folder, call dir.create("/path/unknown", recursive = TRUE)
3: startup::check(): Environment variable 'R_LIBS_SITE' specifies a non-existing folder '/path/unknown' which R ignores and therefore are not used in .libPaths(). To create this folder, call dir.create("/path/unknown", recursive = TRUE)