From e949d758998fafbef608adcf9f54d79a6e7da4c8 Mon Sep 17 00:00:00 2001
From: Jonathan Ringer <jonringer117@gmail.com>
Date: Tue, 17 Nov 2020 09:09:59 -0800
Subject: [PATCH] python2Packages.numpy: fix openblas threads

---
 pkgs/development/python-modules/numpy/1.16.nix | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkgs/development/python-modules/numpy/1.16.nix b/pkgs/development/python-modules/numpy/1.16.nix
index ab4991cad145..1ab958a15f07 100644
--- a/pkgs/development/python-modules/numpy/1.16.nix
+++ b/pkgs/development/python-modules/numpy/1.16.nix
@@ -60,6 +60,7 @@ in buildPythonPackage rec {
   preConfigure = ''
     sed -i 's/-faltivec//' numpy/distutils/system_info.py
     export NPY_NUM_BUILD_JOBS=$NIX_BUILD_CORES
+    export OMP_NUM_THREADS=$((NIX_BUILD_CORES > 64 ? 64 : NIX_BUILD_CORES))
   '';
 
   preBuild = ''