Occasionally after install.packages()
:
Do you want to install from sources the package which needs compilation? (Yes/no/cancel)
What are the implications of not installing a package that needs compilation from source(s)?
What I know so far
I guess it's safer to always select 'Yes', and I suspect this may reinstall (/update) shared libraries or extensions (e.g. c, c++, fortran). Also some very general ideas/advantages listed here