maybe_specific_n = $(if $(filter -j%,$(parallel_opt)),-n$(get_parallel_n))
xdist_opt = $(if $(filter -j,$(parallel_opt)),-nauto,$(maybe_specific_n))
maybe_specific_n = $(if $(filter -j%,$(parallel_opt)),-n$(get_parallel_n))
xdist_opt = $(if $(filter -j,$(parallel_opt)),-nauto,$(maybe_specific_n))