check_cores suggests to use 0 cores #42
Description
We rely on bigstatsr::nb_cores to find the total number of cores. The nb_cores function always uses omit-1, where it takes the total number of processes and substracts one. To do so, it first calls parallelly::availableCores. However, we have found that certain systems will return only 1 available process (when method == "nproc"). In those cases, nb_cores would return 0 useable cores, which trips up our code in check_cores.
Suggestion is to switch to parallel::detectCores.