From 5774ab7d9a4844dc4f1af8df40360a2c87006c98 Mon Sep 17 00:00:00 2001
From: Dilum Aluthge <dilum@aluthge.com>
Date: Sun, 10 Dec 2023 15:14:10 -0500
Subject: [PATCH 1/3] CI: don't run the macOS CI jobs with the MKL provider

---
 .github/workflows/CI.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index f66a5e2..80dc4f2 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -49,6 +49,9 @@ jobs:
             arch: x86
           - provider: 'mkl'
             threads: '2'
+          # In MKL 2024, Intel dropped support for macOS.
+          - os: macOS-latest
+            provider: 'mkl'
 
     steps:
       - uses: actions/checkout@v3

From e50cd7945fae76a0c8fd28fbab398e014c943155 Mon Sep 17 00:00:00 2001
From: Dilum Aluthge <dilum@aluthge.com>
Date: Sun, 10 Dec 2023 16:30:30 -0500
Subject: [PATCH 2/3] CI: for the macOS CI jobs with the MKL provider, force
 MKL_jll 2023 to be installed

---
 .ci/macos_mkl_2023.jl    | 32 ++++++++++++++++++++++++++++++++
 .github/workflows/CI.yml |  9 +++++----
 2 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 .ci/macos_mkl_2023.jl

diff --git a/.ci/macos_mkl_2023.jl b/.ci/macos_mkl_2023.jl
new file mode 100644
index 0000000..32b9871
--- /dev/null
+++ b/.ci/macos_mkl_2023.jl
@@ -0,0 +1,32 @@
+# In MKL 2024, Intel dropped support for macOS.
+# So, in CI, for the macOS jobs, we force MKL 2023 to be installed (instead of
+# MKL 2024).
+
+import TOML
+
+using Test: @test
+
+function main()
+    root_dotci_dir = @__DIR__
+    root_dir = dirname(root_dotci_dir)
+    root_project_toml_filename = joinpath(root_dir, "Project.toml")
+    project = TOML.parsefile(root_project_toml_filename)
+    old_mkl_jll_compat = project["compat"]["MKL_jll"]
+    old_mkl_jll_compat_list = strip.(split(strip(old_mkl_jll_compat), ","))
+
+    # Regression test to catch if we ever drop support for MKL_jll 2023.
+    # Because, if we ever do choose to drop support for MKL_jll 2023, then this
+    # entire script should probably be deleted, since Intel dropped support for
+    # macOS in MKL 2024.
+    @test "2023" in old_mkl_jll_compat_list
+
+    new_compat = "2023"
+    project["compat"]["MKL_jll"] = new_compat # force MKL_jll 2023
+    open(root_project_toml_filename, "w") do io
+        TOML.print(io, project)
+    end
+    @info "Changed the compat entry for MKL_jll to: $(new_compat)"
+    return nothing
+end
+
+main()
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 80dc4f2..f1b99b3 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -49,10 +49,6 @@ jobs:
             arch: x86
           - provider: 'mkl'
             threads: '2'
-          # In MKL 2024, Intel dropped support for macOS.
-          - os: macOS-latest
-            provider: 'mkl'
-
     steps:
       - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@v1
@@ -60,6 +56,11 @@ jobs:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
       - uses: julia-actions/cache@v1
+      # In MKL 2024, Intel dropped support for macOS.
+      # So, in CI, for the macOS jobs, we force MKL 2023 to be installed (instead of
+      # MKL 2024).
+      - run: julia .ci/macos_mkl_2023.jl
+        if: (matrix.os == 'macOS-latest') && (matrix.provider == 'mkl')
       - name: Set Preferences
         run: julia --project .github/set_ci_preferences.jl "${{ matrix.provider }}"
       - uses: julia-actions/julia-runtest@v1

From 4bd5b40a8a733c278c6347fa0e6291e5da691604 Mon Sep 17 00:00:00 2001
From: Dilum Aluthge <dilum@aluthge.com>
Date: Sun, 10 Dec 2023 16:31:34 -0500
Subject: [PATCH 3/3] Restore whitespace

---
 .github/workflows/CI.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index f1b99b3..c2dd225 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -49,6 +49,7 @@ jobs:
             arch: x86
           - provider: 'mkl'
             threads: '2'
+
     steps:
       - uses: actions/checkout@v3
       - uses: julia-actions/setup-julia@v1