toolchain/meson-check-cores.nix
Meson concurrency alone does not bound tests that size their own thread pools from sched_getaffinity(). Keep both within this build's Nix core allocation.
λpkgs
λold
old.preCheck or ""
+
export FUGC_THREADS="$NIX_BUILD_CORES"
filcTestCpus=$(${pkgs.python3}/bin/python3 -c '
import os
cpus = sorted(os.sched_getaffinity(0))
cores = int(os.environ["NIX_BUILD_CORES"])
print(",".join(map(str, cpus[:cores] if cores > 0 else cpus)))
')
mesonCheckFlagsArray+=(--num-processes "$NIX_BUILD_CORES"
--wrapper "${pkgs.util-linuxMinimal}/bin/taskset -c $filcTestCpus")