From 61e57a827b84251bbe4713ea2714a99f9e6f7314 Mon Sep 17 00:00:00 2001
From: Austin Seipp <aseipp@pobox.com>
Date: Thu, 10 Jan 2019 16:08:01 -0600
Subject: [PATCH] icestorm: enableParallelBuilding = true

With the previous PyPy3 change, this reduces the compile time from
~1m30s to roughly 36s (compared to the original, serial, Python 3 build
time of 2:30s).

Signed-off-by: Austin Seipp <aseipp@pobox.com>
---
 pkgs/development/tools/icestorm/default.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/development/tools/icestorm/default.nix b/pkgs/development/tools/icestorm/default.nix
index 64bec03eb4a..0d96ec02c4c 100644
--- a/pkgs/development/tools/icestorm/default.nix
+++ b/pkgs/development/tools/icestorm/default.nix
@@ -24,6 +24,8 @@ stdenv.mkDerivation rec {
   buildInputs = [ pythonPkg libftdi ];
   makeFlags = [ "PREFIX=$(out)" ];
 
+  enableParallelBuilding = true;
+
   # fix icebox_vlog chipdb path. icestorm issue:
   #   https://github.com/cliffordwolf/icestorm/issues/125
   #