Test environments local win10 install, R 4.1.0 Ubuntu 16.04.6 LTS (on travis-ci), R 4.0.2 Ubuntu Linux 20.04.1 LTS, R-release, GCC, R version 4.0.5 (RHub) Fedora Linux, R-devel, clang, gfortran (RHub) R CMD check results There were no ERRORs or WARNINGs.