Add workaround for segfault in MacOS tests (#1184)

.github/workflows/tests.yml

@@ -58,6 +58,7 @@ jobs:
  ln -sfn $(which docker-buildx) $HOME/.docker/cli-plugins/docker-buildx
  colima start --memory 4
  sudo ln -sf $HOME/.colima/default/docker.sock /var/run/docker.sock
+
  - uses: actions/checkout@v3
  - name: Set up Python ${{ matrix.python-version }}
  uses: actions/setup-python@v2
@@ -75,7 +76,7 @@ jobs:
  tox -e ${{ matrix.tox-environment }}
 
  all-runtimes:
- if: github.event_name == 'push'
+ # if: github.event_name == 'push'
  strategy:
  fail-fast: false
  matrix:
@@ -93,6 +94,16 @@ jobs:
  ln -sfn $(which docker-buildx) $HOME/.docker/cli-plugins/docker-buildx
  colima start --memory 4
  sudo ln -sf $HOME/.colima/default/docker.sock /var/run/docker.sock
+ - name: Downgrade OpenMP (in MacOS)
+ if: runner.os == 'macos'
+ run: |
+ # Recent versions of OpenMP cause segfaults in MacOS when training
+ # LightGBM / XGBoost models (but only when Torch is present)
+ # https:/microsoft/LightGBM/issues/4229
+ # https:/autogluon/autogluon/issues/1442
+ wget https://raw.githubusercontent.com/Homebrew/homebrew-core/fb8323f2b170bd4ae97e1bac9bf3e2983af3fdb0/Formula/libomp.rb
+ brew unlink libomp
+ brew install libomp.rb
  - uses: actions/checkout@v3
  - name: Set up Python ${{ matrix.python-version }}
  uses: actions/setup-python@v2