* installing *source* package ‘RGF’ ...
** this is package ‘RGF’ version ‘1.1.1’
** package ‘RGF’ successfully unpacked and MD5 sums checked
** using staged installation
** R
** inst
** byte-compile and prepare package for lazy loading
** help
*** installing help indices
** building package indices
** installing vignettes
** testing if installed package can be loaded from temporary location
warning: Failed to inspect Python interpreter from search path at `/usr/sbin/pypy`
  cause: Can't use Python at `/usr/sbin/pypy`
  cause: Python executable does not support `-I` flag. Please use Python 3.6 or newer.
** testing if installed package can be loaded from final location
warning: Failed to inspect Python interpreter from search path at `/usr/sbin/pypy`
  cause: Can't use Python at `/usr/sbin/pypy`
  cause: Python executable does not support `-I` flag. Please use Python 3.6 or newer.
** testing if installed package keeps a record of temporary installation path
* DONE (RGF)