Allow cpu counting on multiple platforms

Author: rhpvorderman

setup.py

@@ -97,12 +97,15 @@ def build_isa_l():
     build_env = os.environ.copy()
     # Add -fPIC flag to allow static compilation
     build_env["CFLAGS"] = build_env.get("CFLAGS", "") + " -fPIC"
-
+    if hasattr(os, "sched_getaffinity"):
+        cpu_count = len(os.sched_getaffinity(0))
+    else:  # sched_getaffinity not available on all platforms
+        cpu_count = os.cpu_count() or 1  # os.cpu_count() can return None
     run_args = dict(cwd=build_dir, env=build_env)
     subprocess.run(os.path.join(build_dir, "autogen.sh"), **run_args)
     subprocess.run([os.path.join(build_dir, "configure"),
                     "--prefix", temp_prefix], **run_args)
-    subprocess.run(["make", "-j", str(len(os.sched_getaffinity(0)))],
+    subprocess.run(["make", "-j", str(cpu_count)],
                    **run_args)
     subprocess.run(["make", "install"], **run_args)
     shutil.rmtree(build_dir)