Add sklearn way of installing omp

VERSION

@@ -1 +1 @@
-1.1.32.dev4
+1.1.32.dev5

setup.py

@@ -46,21 +46,27 @@ def run_cmd(cmd):
 
 system_name = platform.system()
 if (system_name == "Darwin"):
-    # check if OpenMP is installed
-    no_omp_msg = (
-        "OpenMP is not detected. "
-        "MacOS users should install Homebrew and run 'brew install libomp' "
-        "to install OpenMP. "
-    )
-    try:
-        libomp_info = run_cmd("brew info libomp")
-    except:
-        raise RuntimeError(no_omp_msg)
-    if "Not installed" in libomp_info:
-        raise RuntimeError(no_omp_msg)
+    # if user provides OpenMP install prefix (containing lib/ and include/)
+    if "OPENMP_PREFIX" in os.environ and os.environ["OPENMP_PREFIX"] != "":
+        omp_prefix = os.environ["OPENMP_PREFIX"]
+    # otherwise check brew installation
+    else:
+        # check if OpenMP is installed
+        no_omp_msg = (
+            "OpenMP is not detected. "
+            "MacOS users should install Homebrew and run 'brew install libomp' "
+            "to install OpenMP. "
+        )
+        try:
+            libomp_info = run_cmd("brew info libomp")
+        except:
+            raise RuntimeError(no_omp_msg)
+        if "Not installed" in libomp_info:
+            raise RuntimeError(no_omp_msg)
+
+        # grab include and lib directory
+        omp_prefix = run_cmd("brew --prefix libomp")
 
-    # grab include and lib directory
-    omp_prefix = run_cmd("brew --prefix libomp")
     omp_include = os.path.join(omp_prefix, "include")
     omp_lib = os.path.join(omp_prefix, "lib")
 

tools/wheels/cibw_before_build.sh

@@ -1,14 +1,38 @@
 # install homebrew + libomp
 if [[ "$OSTYPE" == "darwin"* ]]; then
-    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
-    brew install libomp
-
+    # See https://github.com/scikit-learn/scikit-learn/blob/09781c540077a7f1f4f2392c9287e08e479c4f29/build_tools/wheels/build_wheels.sh#L18-L50
     # See https://cibuildwheel.pypa.io/en/stable/faq/#macos-library-dependencies-do-not-satisfy-target-macos
     if [[ "$CIBW_BUILD" == *-macosx_arm64 ]]; then
-        echo "yay"
-        export MACOSX_DEPLOYMENT_TARGET=14.0
+        # install conda
+        set -ex
+        # macos arm64 runners do not have conda installed. Thus we much install conda manually
+        EXPECTED_SHA="dd832d8a65a861b5592b2cf1d55f26031f7c1491b30321754443931e7b1e6832"
+        MINIFORGE_URL="https://github.com/conda-forge/miniforge/releases/download/23.11.0-0/Mambaforge-23.11.0-0-MacOSX-arm64.sh"
+        curl -L --retry 10 $MINIFORGE_URL -o miniforge.sh
+
+        # Check SHA
+        file_sha=$(shasum -a 256 miniforge.sh | awk '{print $1}')
+        if [ "$EXPECTED_SHA" != "$file_sha" ]; then
+            echo "SHA values did not match!"
+            exit 1
+        fi
+
+        # Install miniforge
+        MINIFORGE_PATH=$HOME/miniforge
+        bash ./miniforge.sh -b -p $MINIFORGE_PATH
+        echo "$MINIFORGE_PATH/bin" >> $GITHUB_PATH
+        echo "CONDA_HOME=$MINIFORGE_PATH" >> $GITHUB_ENV
+
+        export MACOSX_DEPLOYMENT_TARGET=12.0
+        OPENMP_URL="https://anaconda.org/conda-forge/llvm-openmp/11.1.0/download/osx-arm64/llvm-openmp-11.1.0-hf3c4609_1.tar.bz2"
     else
-        echo "no yay"
-        export MACOSX_DEPLOYMENT_TARGET=13
+        # Non-macos arm64 envrionments already have conda installed
+        echo "CONDA_HOME=/usr/local/miniconda" >> $GITHUB_ENV
+
+        export MACOSX_DEPLOYMENT_TARGET=10.9
+        OPENMP_URL="https://anaconda.org/conda-forge/llvm-openmp/11.1.0/download/osx-64/llvm-openmp-11.1.0-hda6cdc1_1.tar.bz2"
     fi
+
+    sudo conda create -n build $OPENMP_URL
+    OPENMP_PREFIX="$CONDA_HOME/envs/build"
 fi