From 866eedcb69fbdd3c4fe278210deb008a027bce1f Mon Sep 17 00:00:00 2001
From: Wael Nasreddine <wael.nasreddine@gmail.com>
Date: Wed, 12 Aug 2020 10:47:01 -0700
Subject: [PATCH] bazel_3: use less resources when building Bazel (#95214)

Limit the resources Bazel is allowed to use during the build to 1/2 the
available RAM and 3/4 the available CPU cores. This should help avoid
overwhelming the build machine.
---
 .../tools/build-managers/bazel/bazel_3/default.nix          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/pkgs/development/tools/build-managers/bazel/bazel_3/default.nix b/pkgs/development/tools/build-managers/bazel/bazel_3/default.nix
index 60c1662f9ff5..845469e1c7dd 100644
--- a/pkgs/development/tools/build-managers/bazel/bazel_3/default.nix
+++ b/pkgs/development/tools/build-managers/bazel/bazel_3/default.nix
@@ -419,6 +419,12 @@ stdenv.mkDerivation rec {
 
       # add nix environment vars to .bazelrc
       cat >> .bazelrc <<EOF
+      # Limit the resources Bazel is allowed to use during the build to 1/2 the
+      # available RAM and 3/4 the available CPU cores. This should help avoid
+      # overwhelming the build machine.
+      build --local_ram_resources=HOST_RAM*.5
+      build --local_cpu_resources=HOST_CPUS*.75
+
       build --distdir=${distDir}
       fetch --distdir=${distDir}
       build --copt="$(echo $NIX_CFLAGS_COMPILE | sed -e 's/ /" --copt="/g')"