From 5a5577c28b4a2c3cf5f92c8a5920e0770ad2c41a Mon Sep 17 00:00:00 2001
From: Hyunsu Cho <chohyu01@cs.washington.edu>
Date: Wed, 14 Jul 2021 18:25:40 -0700
Subject: [PATCH] [CI] Downgrade libomp to 11.1.0

---
 .travis.yml           | 8 +-------
 tests/travis/setup.sh | 6 ++++++
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 53f0c75d..60c8e729 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,13 +28,7 @@ jobs:
 # dependent brew packages
 addons:
   homebrew:
-    packages:
-      - cmake
-      - libomp
-      - wget
-      - lcov
-      - ninja
-    update: true
+    update: false
   apt:
     sources:
       - sourceline: 'deb https://apt.kitware.com/ubuntu/ bionic main'
diff --git a/tests/travis/setup.sh b/tests/travis/setup.sh
index d89b05e2..a7b0a2e0 100755
--- a/tests/travis/setup.sh
+++ b/tests/travis/setup.sh
@@ -3,6 +3,12 @@
 set -eo pipefail
 
 if [ ${TRAVIS_OS_NAME} == "osx" ]; then
+  brew update
+  # Use libomp 11.1.0: https://github.com/dmlc/xgboost/issues/7039
+  wget https://raw.githubusercontent.com/Homebrew/homebrew-core/679923b4eb48a8dc7ecc1f05d06063cd79b3fc00/Formula/libomp.rb -O $(find $(brew --repository) -name libomp.rb)
+  brew install cmake libomp lcov ninja
+  brew pin libomp
+
   wget -O conda.sh https://repo.anaconda.com/miniconda/Miniconda3-latest-MacOSX-x86_64.sh
 else
   wget -O conda.sh https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh