feat(initial): added portable mfem build system

tools/run_mpi_test.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+"""Run one MPI test without baking a particular MPI launcher into the meson build tree."""
+
+from __future__ import annotations
+
+import argparse
+import os
+import sys
+import subprocess
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--launcher", required=True)
+    parser.add_argument("--processes", type=int, default=2)
+    parser.add_argument("executable")
+    parser.add_argument("arguments", nargs="*")
+    args = parser.parse_args()
+    command = [args.launcher, "-n", str(args.processes), args.executable, *args.arguments]
+    environment = dict(os.environ)
+    environment.setdefault("OMPI_ALLOW_RUN_AS_ROOT", "1")
+    environment.setdefault("OMPI_ALLOW_RUN_AS_ROOT_CONFIRM", "1")
+    loopback = "lo0" if sys.platform == "darwin" else "lo"
+    environment.setdefault("FI_PROVIDER", "sockets")
+    environment.setdefault("FI_SOCKETS_IFACE", loopback)
+    environment.setdefault("HYDRA_IFACE", loopback)
+    if sys.platform == "darwin":
+        environment.setdefault("MPICH_INTERFACE_HOSTNAME", "127.0.0.1")
+    return subprocess.run(command, env=environment, check=False).returncode
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())